>>13525781its pretty straight forward to me
geodude has its 2 arms
graveler has 4 arms, the two long outer arms are the arms it had as a geodude, the smaller ones are undeveloped and just starting to emerge as are the legs. also the beginnings of a forehead
golem has 2 arms, upon evolution it sheds the arms it had as a geodude and the other arms as well as the legs finish developing, and its head fully emerges from the body