date might help in some cases, but it’s not going to always going to satisfy the needs described in this thread. even if i have only one observation that day, suppose i take 50 photos and use 2 of those 50 in the observation. in order to figure out if any of the photos taken that day were used in a particular observation, currently, i would still have to open up the observation and look at each of the 2 uploaded photos in detail to figure out which of the 50 image files they came from.
the other complicating factor is that depending on how you upload, often the time that’s recorded in iNaturalist is precise only to the minute (not to the second). so, similar to the situation above, if you’ve taken 10 photos in that particular minute, and you only uploaded 2 photos, there’s still not a great way to automate the association of those 2 uploaded photos to the 10 original photos from your personal collection.