The arms are probably chrome to invite attention and imply motion. "Hey, play with me, I move!" It's a signal to potential buyers that they're not looking at yet another all-in-one computer. I think it's a smart choice. If you're staring at the arms enough to be bothered, then you're probably not the target market for this device; the arms are completely hidden when used in drafting/drawing profile.

For what it's worth, Apple created a similarly attention-grabbing hinge on their G4 iMac back in the day.