It's a minor glitch, but for some reason, the Dream Stealer Sigils don't show in the playing interface when I walk around the festival zone. It does show in the wardrobe, my profile, etc. though. Just wondering if it might be a glitch or something warranting investigation. :-)

This came up last year, and is explained in this thread.

Basically, the sigil is a "background", layered behind the wings, and backgrounds don't show up while exploring. Same thing goes for the shadow stalkers.