Well, tea-residue face, I guess.
It’s clearly a face, but for me it’s the first such face-by-pareidolia not triggered by eyes. I wrote that sentence a few ways to avoid the tricky question of the adjectival form of pareidolia. Pareidolic? Pareidoliac? The former sounds like parabolic, the latter evokes maniac. Neither sounds quite right, although at least the latter would offer an obvious theme song.