This tiny cover of Nintendo Power is too small to show much, other than that it has Sonic, and relates to Sonic Adventure 2 Battle. If you have a larger scan, it can replace this small image. 

And the larger scan is found! It's found in the gallary at the right, or top if you're on mobile. Around the release of Sonic Adventure 2 Battle, Nintendo Power chose Sonic (in his soap shoes) to be the solo star of their magazine cover. The logo for the game appears, and they talk about how they'll cover it inside. Notice the background/gray is a Sonic spin swirl shape. Sonic covers are always great to collect!