Minecraft Skin Messed Up
I believe this is just a problem with loading skins, as sometimes this happens to me when I join a server, my skin only shows the inner layer, but soon after it loads the second layer, also I noticed the NPC's behind you don't have there skins ether. One other possibility is that you might have the skin layer turned off in settings.
Thats I can think of that would be wrong, if you have anymore questions feel free to ask me!