This is a detail of an all-black shirt, currently in the SonicGear collection. Sonic's pose is slightly different, with one thumb up and a fist. The background is just curly designs in white with blue 'glow' effect. There are also subtle lines (Like linescreen) behind that. The shirt is otherwise plain and black, and looks like every other plain black shirt you've seen. The design is fairly large, and sits right in the middle of the chest area.