Unless folks are adding value to “Observation Fields” &/or “Life Stage”, it’s difficult to sort between pictures of tracks/sign and actual pictures of the organism.
The way I normally filter out tracks/sign is by viewing an observation (any observation) of a feather, bone, set of tracks, etc. & clicking on “How was this Detected” under “Observation Fields”. There is a pop-up menu that appears and then I usually click on the second arrow in the “View:” menu, “-> Observations with this field”.
That should take you to this page: https://www.inaturalist.org/observations?verifiable=any&place_id=any&field:How%20was%20this%20Detected%3F
At this point, you can filter out by place and/or organism. Seems kind of a workaround but it works. Also, this is the reason why adding value to observations is so helpful down the line for anyone who has the same query as you do. Whenever possible I try to add value by marking organisms’ alive/dead, how was this detected, likely cause of death, etc. observation fields. You can also filter out organisms by life stage, sex, and dead/living by clicking on any of the attributes in the “Annotations” box.