Tom is wandering. London's a big city; wandering's a decent way to spend an afternoon, when you've got no classes and your homework's done and you don't have any friends you'd rather spend the time with because everyone around you is a contemptible idiot you're the kind of introvert who needs a bit of solitude to recharge. He's glancing at the shops he passes, in case any seem more interesting than the walk. Miracles do happen*.

*No they don't. Magic isn't real and neither is God.