That’s a crochet daisy (or sunflower) granny square pattern — it has long loop petals and a tightly stitched center. 🌻
Here’s a step-by-step guide to make it:

Materials & gauge

Yarn: DK / light worsted (or similar). If using finer yarn, use a smaller hook.
- Suggested: DK weight yarn for flower body, contrasting color for square border.
Hook: 3.5 mm (E) — adjust to get a firm center but flexible loops.
Small amount of brown yarn for the tiny center eye (or you can embroider it).
Tapestry needle, scissors, optional stitch marker.
Abbreviations: MR = magic ring, ch = chain, sc = single crochet, sl st = slip stitch, dc = double crochet.

Overview of structure

Small brown center “eye”
Green circle around the eye (two rounds)
Loop petals attached around the green round (16 loops)
A round of single crochet to tidy petal bases
White border worked into a square (corners and sides)

Pattern — 16-petal version

CENTER EYE (brown)

MR, 6 sc into MR. Pull tight. (6)
Sl st to first sc to join. Fasten off brown and change to green yarn.

Small note: 6 sc gives a compact center eye similar to the photo. If you want a slightly larger eye, start with 8 sc and proceed the same.

GREEN ROUNDS (to make the disk under petals)

With green attached to any stitch of the brown round: Round 1 (green): 2 sc in each stitch around. (6 × 2 = 12 sc). Join with sl st.
Round 2 (green): sc in each st around (12 sc). Join with sl st.
Round 3 (green) — optional beef up: If you want a thicker green disk, do 1 sc in each st again (12 sc). Fasten off green (or leave attached if you prefer).

This produces a solid small disk about the size shown in the photo.

LOOP PETALS (yellow / petal color)

We’ll make 16 loop petals. The loop length below matches the photo; change length to suit your taste.

Attach petal color in the back loop or at the base of any green stitch. Optional: place a marker in the stitch you attach to so you don’t lose your starting point.
Work the petals around the green disk like this:

Ch 12, skip 1 green stitch, insert hook into the next green stitch and sl st (or sl st in same stitch as explained below) to secure the chain forming a loop.
Repeat ch 12, sl st in next stitch until you have 16 loops total.

Important detail: There are two common ways to anchor loops:

(A) Anchor into the next stitch: ch 12, insert into next green stitch, sl st — this will give one loop per green stitch and cause the loops to sit between foundation stitches.
(B) Anchor into same stitch as base: ch 12, insert into the same stitch you started the chain, sl st — this makes the loop sit directly above a base stitch.
Either method works; the photo-style look typically uses method (A).

After completing the round you should have 16 wide chain loops evenly spaced.

TIDY THE LOOPS (secure them and make a clean petal base)

Turn your work to the back (optional) or stay on the front depending on how you like the look. With the petal color still on the hook, work 1 sc in each green stitch around the base (12 sc if you used 12 green stitches, but because we made 16 loops we spaced them across the green — if you used 12 green stitches and made 16 loops you’ll need to space them, so the tidy round is “sc into the st or between st where loops are anchored” — the goal: 1 sc at each loop base). Count carefully: you should have 16 sc around the loop bases (one sc under each loop). Join with sl st, fasten off or carry yarn.
Optional decorative round: sc, ch1 around or make tiny slip-stitch picots between petals to mimic the little green picot look in the photo: (sc in base, ch1) repeat around, join.

Optional: Add a little raised brown button/eye

If you want the raised brown center like the image:

With brown yarn and smaller hook or embroidery, use 6-dc bobble worked into the very center before you joined the green — or simply embroider a small knot: wrap brown yarn several times around your finger to make a small coil, sew it in place in the center and stitch securely. This gives the little brown “eye” highlight.

TURNING INTO A SQUARE (white border)

We’ll convert the circular flower into a 10 cm-ish granny square by spacing corners evenly.

Attach white yarn on the back of a petal base stitch (or in any sc between petals). You will work 4 sides with 4 corners. Each side will use groups of dc to form a square.
Round for square (worked in the round; counts are approximate because loop spacing may vary — I give a stable method):

Start: ch 1 (counts as no stitch), sc into same stitch to anchor.
For the first corner: ch 3, (3 dc, ch 2, 3 dc) into the same spot (this is corner cluster).
Now work along side: skip 1 or 2 small stitches as needed, then 3 dc into the space between petal bases for a short side cluster, ch 1 between clusters. Continue across until you reach the next corner point.
At the next corner position (you want 4 roughly even corners — place them every 4 loops for 16 loops), do (3 dc, ch 2, 3 dc) again.
Continue around to form 4 sides. Join with sl st and fasten off.

Exact placement rule: With 16 loops, make corners after loops 4, 8, 12, and 16 (i.e., every 4 loops) so the square is even.

Optional second round of white: On each side between corners work 3 dc, ch1, 3 dc to widen the square, or simply do 1 round of dc in each stitch with ch-1 spaces at corners to square up. Block the square to perfect the shape.

Finishing

Weave in ends with tapestry needle on the back.
Gently steam-block or wet-block to open the loops and shape the square. Pin to measurements while drying for a neat square.
If loops are too floppy, use a slightly smaller hook size for the chains next time or add a tiny slip-stitch stitch across the top of each loop (invisible from the front) to reduce stretch.

Variations & tips

Number of petals: For a fuller flower use 24 loops (space them across a wider initial green round by increasing initial green rounds to 12 or 24 sts). To convert to 24 loops: make Round2 green = 12 → Round3 increase to 24 sc, then ch-loop into each stitch for 24 petals.
Loop length: ch10 → shorter petals; ch14–16 → longer petals.
Petal fullness: make two rounds of loops (one loop between each existing loop) to create a double-row petal look.
Yarn & hook: tighter hook = neater center; looser hook = softer, bigger petals.

Step-by-step to make crochet granny square sunflower