It seems kind of weird that you can't tell, but this dress could be for either a boy or a girl. Small boys wore dresses until they were about six, and then they would dress more like a boy in trousers. This dress is small enough that it could be for either. To me, it looks like a boy's dress, just because of the pleats all over the place.
Long sleeves, with pleats on the armscye and the wrist. Knife pleats on the bodice, with double inverted box pleats around the skirt. Black trim on the cuffs, waistband, skirt edge, and on the shoulder edge. It's pretty cute.