The first guy is showing the skin.
The second guy... the nervous system
The third guy.... the muscles
The fourth guy... the bones
And the last guy... the digestive system
I know you can't really see it well, but he did a really good job with it and when you look at it you can see all the parts that he put.
I like seeing these little things. It makes me happy to know that they are listening... even sometimes when I don't think they are.