The cases I saw where the bakeries were ruled against, it sounded like they refused to bake them a cake, not about the cake decorations.
Now wedding photography is a more difficult one to get around, its about taking images of the same sex couple.
The new rights and the religious beliefs (against gay marriage) are right on top conflicting with one another.
Maybe they could require a certain dress standard in the photos, must wear a bride and grooms outfits.
The ones I’ve read of here on FR, each case was that they explicitly refused to bake a cake explicitly decorated to support a sodomite wedding.
And in at least one case, the sodomites who sued were longstanding customers of the Christian bakery which they sued.