User photos are added to the taxon description manually and can only be chosen from research grade images. If there are no user based research grade images of sufficient quality external images may be used, provided they’re properly sourced (not sure how that’s decided, probably a curator or mod issue).
If there is a species description that’s lacking images (or has bad ones) and you know of users who have better photos of research grade observations (including your own) that make the ID process easier then you can add those to the species description page, but that doesn’t happen automatically, and it should only be done it there are no existing images or if there are ones that are clearly better than what exists.
I have quite a few images, and have added more from other users, that are the default species page images because there weren’t any images in the species description. Sometimes I’ll some across a research grade user ID image that’s better than mine and I’ll change it so that’s the default image instead.
Back in the early days, iNat staff would add some pics to the taxon pages from Flickr and perhaps others sources that were Creative Commons. They added a few of mine before I later submitted them to iNat as records.
Mr. Roncal probably set the observation as casual due to herbarium issues or something. He is working with an herbarium at the University of Cajamarca. He was working on adding the other photo at the moment I think, as the date is missing
Edited because mistook (casual) as (deleted)
Edit2: The photos were from another observation, this link isn’t the original where it was determined as Esenbeckia. That’s why there is no other obs. linked from these photos, the original was deleted indeed
Not true? Photos can be added to taxa by any user using Curation->Edit Photos from observations even if they’re not Research Grade:
and even if not properly sourced. (Photos from Flickr can be suggested based on nearby text, so if someone wrote “thought this was species X, but it isn’t” that’s enough to get it suggested for species X - so beware!)