The subject of shapes doesn't stank out to me in this photo, in fact the "sphere is lost in the sand or snow. I understand the play on words and still just doesn't make it for me.
Not a strong emphasis on shape here, far too many distractions. (The image could work as is for different purposes though.)
To emphasise the shape, you could try framing so that you have only the rock and the hand holding it, or perhaps the rock, hand and the model's head (trying to find similarity in the shapes of the head and the rock). Make sure your model takes off the backpack though, so that the objects sticking up from it don't distract attention from the shapes.
The object in the person's hand is about the last thing my eyes settle on in this image. It's a nice photograph of a person -- lots of life -- but for this particular challenge I think it falls a bit short. 5.
I wish your sphere was a little more prominent in this shot. It is not clear what it is (a coconut perhaps?) or why it makes the holder so happy. (Great expression though.) Also the coloring is a little drab.
This photo appears to be an awesome record of an exciting event. The placement of the person in the shot is great and there are interesting colors and textures in the background. I'm asking, "What is the sphere?" and "Do I want one too?" As a candid shot, you've definately captured the moment. As a piece of art, the photo needs a slightly different treatment of the skyline - incorporate more or remove it. (If this is a scientific find, I'm right there celebrating with you -and definately post this shot in your office/lab.)