Photos / videos taken by the game (the traps) / the oraganisations in the game (the Academy detention camera and stuff set up by the Academy in the Extra Credit Zone) can be deleted, as these are uploaded to accounts controlled by Nintendolls.
Photos / videos taken by other people (bystanders / dashcams in the Extra Credit Zone and real life friends who video call you via the video call traps) were not uploaded by Nintendolls and therefore can't be deleted via that interface (or, currently, at all).
I've had a few people report this bug but have yet to be able to replicate it myself