I was testing some F3 commands in a multiplayer server when I decided to toggle entity hitboxes by pressing F3 and B at the same time. I heard about this command on minecraft wiki (http://minecraft.gamepedia.com/Minecraft_Wiki). When I opened my inventory (pressing E) with the hitboxes on I found that the hitbox around my character was shifted upwards. I was not sure whether this is a problem, but I decided to report it just in case. I will attach a screenshot.