Sounds like a fun lab!
I predicted it was a boy from the pic! I wonder how hard it is to make that prediction. Would most humans make the correct prediction? If yes, then an app that shows pics of children and asks the user to sort them as a kind of game, would be an effective and cheap and safe sex-determination app!
Most of my class guessed boy too based on the pic. I kinda assumed it'd be harder to guess, but there must just be something about the features of him that make him look like a boy.
Thanks for reading!