Two suggestions. #1 seems feasible but large, #2 is way too specific and probably no one but me would use it, but I’ll throw it out there anyway.
1. Add a “Projects” tab. Similar to the “Observations” and “Species” tabs, it could include all projects within your search area (probably limited to 500, like the others). They could be ranked by observations and species, separately or together, although separately would be preferable. Clicking the “x observations” link for a project could automatically populate the project search bar with the project ID, similar to how clicking that link for a species fills in the species search. The projects would be subject to any and all search parameters you impose, including specific species, Wild / Captive and certain users’ observations.
2. Within the “Your Observations” search, species view, use your own photos as taxon photos.
I told you this was niche. I’ve been thinking about it for a while, but didn’t post because it seemed like a waste of time. Then I saw this topic, which is the exact same request but for your life list (where it makes much more sense). However, that wasn’t good enough for me, because I don’t like iNaturalist’s life lists. They’re confusingly organized and just don’t make sense to me. All I want is a nice, simple display of your species observed, filterable, easy to understand. So I use the “Your Observations” filter on Explore in place of my life list. I’m looking for exactly the same functionality as described in the linked feature request, but for that page.