When file deletion is enabled, “Delete” shows up in the “…” menu on the dashboard-view. But if you click on the photo to view it in full/slideshow mode (e.g. if you want to make sure it’s the one you want to delete) the “…” menu does not have “Delete” as an option.
This makes it challenging to clean up my photo library because I want to keep one of several photos that have very small differences (closed eyes, a smile, etc) that I cannot see without viewing in full-screen mode, but when I do so I cannot delete, so I need to remember which I clicked on when I return to the dashboard.