This is a large cardboard stand up for Sonic Heroes. You can see how big it is here, as it's on a door. It features 3 raised cardboard disks (removable, probably for shipping) of teams Dark, Rose & Chaotix. The center is scored so the whole thing can fold. The border has "Sonic Team" written all around it and the Sonic head icon above the screenshots says "All New Sonic". The slogan in the middle is "Join the TEAM!" It has four screenshots total, so you can see what the game itself will look like. (Always a good idea) The copyright info at the bottom has the rating (E), and all relevant system/developer logos.
This was seen at Gamecrazy & Hollywood Video stores as a promotion. It may not have been at other retail areas, so it seems uncommon. It's a good colorful representation with 3D elements too. Nice to collect and display, if you can find one.