It's a Sonic Pinball Party Poster!
In Japan, even portable games get retail display posters made for them. This features Sonic, NiGHTS & Amigo the monkey from Samba De Amigo rythmn game. The pinball stages all had themes & cameos from other Sonic Team games. There's a big headline, large logo & several screen shots at the bottom. The chao is shown thinking about how you could play on the Game Cube or the GBA with this game. The blue bar at the bottom of the poster also has a small announcement for Sonic X the TV show along with a date. (Interesting to see, seems the first time it happens)