Along with the new character and Amiibo integration announcements for Super Smash Bros. 4, Nintendo has also released the box art for the two games. The Wii U box art features a logo with blue flames and the characters charging forward; on the other hand, the 3DS box art features a logo with red flames and the characters lined up for battle.

Wii U Smash Box Art
3DS Smash Box Art
A very large image of the Wii U box art is below (click to enlarge).