This pack turns item frames and paintings into 3D models, similar to Vanilla Tweaks' 3D Items texture pack.
This pack partially requires either Optifine or other mods that replicate it's features like CIT Resewn, for the full intended experience, since it uses CIT to make models for each of the individual paintings. Without Optifine, all of those will just appear as the blank painting.

If you have a texture pack that changes the item frame model to have a texture other than birch planks as it's outer border, then the 3D item will be slightly inaccurate to the placed one. Every other texture should work just fine though.