I feel like Charlie finding the Golden Ticket to Willy Wonka's chocolate factory!!
I found the Ultimate Reference to previous Double Fine games:
In the TV room in the Lodge are two potted plants. On each of the pots is the word "Chuck"! It's a reference to LeChuck from the Monkey Island games.
It's hard to see unless you have Levitation and use the light from your Levitation Ball (I set mine to the color white for just this purpose throughout the game) to illuminate the pots. I also used Photoshop to boost up the brightness of the image to better show the word on the pot.
There are more potted plants in the Camp and all have the word "Chuck" written on them.
edited to add:
And looking at this screen cap, I just noticed the wallpaper. Isn't that similar to the background in the Double Fine logo/credit when Psychonauts starts?
The potted plants leads to a trivia question...see the "Psychonauts Quiz" discussion in this forum.