For mobs such as sheep, shulkers, and horses/donkies/mules, all have layers to them. For sheep, you should be able to toggle the wool, for shulkers you should be able to toggle the outer shell (preferably just have an open state instead), and for horses/donkies/mules you should be able to toggle the saddle, leads, etc so that you can get a better view of them. As of now, you can't even see what the inside of someone's shulker texture (The Head I believe) looks like unless there is transparency, has missing pixels, etc. Some mobs are just hard to see unless you are in-game using them.