Hina Face is a meme based on the official image of Hina found in Touhou 10 – Mountain of Faith. Placing Hina in an image creates awkward situations and a sense of discomfort. She is also often a subject of facebombs, as her stare will turn anyone into a replica of herself, in a similar fashion to Weegee.
Hina’s :D grin in that particular image is incredibly derpy and goofy looking, even for ZUN’s hilariously bad art in that game, and attained some notoriety with fans on both sides of the pond.