She hums as a way of saying 'yes', turning a bit awkwardly on Robin's shoulders to get a better look at the altered one. She doesn't touch it just yet, she'll definitely say so before she does.

"How come you altered it like this?" Clara asks, only to realize that might have sounded rude. "N-Not that I don't like it! The mechanism looks really interesting..."

"Does it work like a normal prosthetic?"