Can each variant of a product have its own photo?

Yes. For a Variable product:

1. Open the product and go to the Variants card.
2. In the variant table, find the Image column and click the ＋ box on the row, for example "Red".
3. Pick or upload the photo in the media library.
4. Repeat for the other variants, then click Save.

On your store, the gallery switches to that photo when a shopper picks the variant. Variants without their own image use the product's main photos.

Tip: if several sizes share a colour, give each of those rows the same colour photo.