I use Nextcloud for many years now and for many different use-cases, but photos is not part of it. Mostly because my Nextcloud runs on a SSD and my photos are too many. In addition, I feel like the Nextcloud performance and feature set would not be able to deliver a good user-experience.

So if we are talking a just about a few hundred MB of photos, you are probably fine, but for anything larger I would recommend to consider one of the more specialized projects.