Anything that has been overlooked or that hasn't been noticed before is unrecognized. Your brother may insist that his unrecognized singing talent will make him famous some day, despite the fact that he can barely carry a tune.
Things that simply haven't been discovered yet are unrecognized, like an unrecognized case of pneumonia that doctors initially diagnosed as a bad cold. And qualities that aren't given the proper amount of attention are also unrecognized. It wasn't until your soccer coach had you sub in for an injured forward that she discovered your unrecognized talent for playing offense.