Seriously, I have no idea what makes you think that's Emma Watson. I even have a photo of her here in this month's Empire magazine, not that I need a comparison to realise this is nothing like her.
I have half a mind to approve this since this is used as a reference for on-topic drawings and there are one or two others that are reference photos on here. If the flagger is going to find every last one of them and flag them, then I'll leave this alone, otherwise I'll be approving this.