What a reference does
A reference image anchors the subject: shape, label, materials, colors. With it, your prompt only needs to describe the change — background, light, scene — instead of re-describing the product. Reference-less prompts invent; referenced prompts preserve.
Picking reference #1
Use the cleanest packshot you have: whole product in frame, even lighting, no busy background. Formats accepted: PNG, JPEG, or static WebP, up to 10 MiB each; images are re-encoded server-side with metadata stripped.
- Do: front-facing, in-focus, label readable.
- Don't: heavy filters, motion blur, watermarks, collages.
When reference #2 helps
Add a second image only when it carries information the first lacks — a texture swatch, a color card, a detail close-up. Two angles of the same product just split the model's attention.
Prompting against a reference
Write the delta, not the object. “Same bottle, on a stone ledge with hard morning light” beats re-describing the bottle. And remember: references are shared by every prompt line in the batch, so a batch with references is a set of variations on one anchored product.