Throughout the courses, Professor Oak will mention 'Pokémon Signs' – rock formations or natural features that resemble specific Pokémon. Photographing these signs is an optional challenge that adds to your completion.
There are six Pokémon Signs to find: Kingler (Beach), Pinsir (Tunnel), Koffing (Volcano), Cubone (River), Starmie (Cave), and Dugtrio (Valley). Each sign is a unique rock formation. You need to get a clear photo of the entire formation for Professor Oak to recognize it. They don't give points, but they are a fun collectible.