Continuity mistake: The actual width between the two front large wood bed posts in Harry's room at the Leaky Cauldron inexplicably changes between shots, as do their position on the wood plank floor! Here's what happens: after Harry removes his shoe and dangles it in the first overhead shot, there are five specific wood planks between the posts. Yet when he drops the shoe in the next overhead shot, there are now over five and a half wood planks between the two posts. The left post has moved to the right - by 1/2 a wood plank and the right post actually moved over one whole plank!!
Picture added by Super Grover