According to Osho, we make funny faces because any face is a mask; deep down our being has no face. Consciousness is formless, so a fixed visage feels false and unsatisfying. Playfully distorting the face hints at the inner sense that we are 'bigger than this,' beyond appearances. Recognizing the 'original face' frees us from obsession with looks and shallow judgments.
We pull silly faces because inside we aren’t a face at all, so we play with the mask.