It's not the standard sign, so I'm not sure what it's trying to tell me. I'm guessing there's a diaper-changing station and it's a single-seat bathroom. Or maybe the seats are child-height?
But I'm not sure it's an issue in a place with a repeat userbase--the kids at a daycare, for example, will figure it out. However, at a skating rink or other place with a rotating userbase, it's confusing and unclear.