We expected the skins menu to always show the player in a neutral standing pose. When the player was in a different pose (sitting in a minecart or a boat, crouching or sneaking, for example) when most previously quitting out of the world, then some of the skins menu models will show player models having that last pose instead of having a neutral standing pose. This seems to affect single and multiplayer, creative and survival.

To Reproduce

Original report
When riding a boat and left the game and check the SKIN PACK turned BOAT ANIMATION. Bush 10.0 MyTablet

To Reproduce
Go to a world and ride a boat
Leave the game
Go option and look at the Skin packs
The Skin packs Skin turn Boat Animation