Sure they're in game screenshots, but the resolution of the image is most likely the resolution of the game running on the console. (n4g.com)
Nintendo also showcased Splatoon running on the console, however, it is still unconfirmed that its Splatoon or its sequel. (segmentnext.com)
However, none of this appreciates the fact that this is a full console game running on a console which is the same size of the Blu - ray drives you'd usually put your DOOM disc into. (wccftech.com)