Query string value shown on top-left of wardrobe page

Whatever's between /wardrobe/[xyz]/collection/ in the URL is outputted at the top of the page:
https://basenotes.com/wardrobe/sproaty.26213135/collection/

I discovered the 'username' portion of the URL doesn't do anything if you change it (user ID is used, I assume) but this gets outputted to when changed:
https://basenotes.com/wardrobe/sprtretgrgrdoaty.26213135/collection/