Anna Gaskell photograph

I believe that the girl in this photograph is yawning, it is widely accepted that seeing someone yawning triggers a responsive yawn, and I can honestly say that I yawned after seeing this photograph. However, whether or not she is yawning is unknown. She is holding her hand to her mouth as if she was yawning, however her facial expression is hidden in shadow, meaning that she could be doing something else, she could holding her hand to her mouth in fright at the sight of seeing something.