Open gallery, tap into Pesto, scroll down to Coconut rice, and tap into it. Notice how the user can't see the back icon in upper left.

If the image is dark, then the user can see the back arrow. If the image is light (as is the case with cococut rice), then the user can't see the back arrow.

Strawman solution: put a dark gradient at the top of every image, such that it provides a good contrast for the back arrow. But, of course, open to ideas.