It's more practical to ask you, because you can, but you haven't just yet.

( A soft emphasis on "because." )

You can change your look like a hat, but you've looked the same both times I've seen you. There must be something about how you look now that's comfortable.

( From what he knows of wizards, particularly those of the West, they're wont to change for the occasion, but not if they're partial to their current look - same as anyone else. )