That photo certainly lends itself for both: a direct side-by-side comparison as well as an inspiring combination.
Imagine for plant ID purposes...photos comparing twig structure, for example, or several different species' individual leaves...those would be useful comparisons but not remotely related to the plant combo idea (and now that the plant combo thing is finally working as intended, I'd sure be reluctant to suggest that it get confused again
)
I've seen folks do collage photos to show seasonal and/or time variation and thread updates to a particular database photo is a great idea too.
