Comment by Izkata
Back when they were first coming out, a lot of us also considered GameBoy Pocket to be a new "generation". I think it might have supported a few more shades of grey from the original? And better battery life. And lots of case colors.
Capabilities wise, it was identical to the original Game Boy. Just four shades of gray for games to draw in. Externally: smaller unit, better battery life, higher contrast screen, new link port (yay adapters for connecting to the original Game Boy...), and "Play It Loud" (the colored cases to choose from). A true revision, no room to question about leaps in gaming technology. :)