For me this is NOT an issue either. I review and sort out my photos locally on my PC with my imaging software and create collections of those photos which I think are finals that I upload to ZF.
Anyway, occassionaly it happens that I want to delete one or a view photos which on the previous they have look good enough but the other day I think they are horrible. Than I think its easy to go to this gallery in edit view, double click on a thumbnail that could be the one photo and see this one as single big photo. If I'm not sure about this photo I can click through the photos one by one back and forward until I find the one to be deleted.