The Curator of mastodon.art boosts lots of interesting posts by artists from across the Fediverse. You can follow them at:
As well as pictures, they also recommend creators of interesting photos, videos, audio etc.
This is maybe the best account to follow if you want to discover art on the Fediverse, highly recommended 👍
This is a brand new server run by the main developers of the project as a spin-off of mastodon.social It is not focused on any particular niche interest - everyone is welcome as long as you follow our code of conduct!