Solvers had to look at our avatars on the Mathcamp Slack. They had hidden letters in them, spelling the message NEATLY DRAWN.
A lesson learned from this puzzle: it is hard to reliably testsolve puzzles that depend on the hunt website, location-specific info, etc. With little else to go on, testsolvers quickly asked me whether Mathcamp had virtual avatars. But during the hunt, solvers had a wealth of other information to look at, e.g. the credits page and opening skit. During the hunt, I pushed an emergency clue. In the future I'll know to always do a testsolve on this type of puzzle on the final version of the website.