[Ianto doesn't protest, because he's very aware Jack must have other memories of this room, of the handcuffs and everything else in the drawer. Good. He hopes looking at it hurts. He's a bit surprised about the metal handcuffs to be honest; in his experience Jack usually prefers leather and he has no way of knowing they're a response to Spike.
And while she may have more pop culture it's from after his time so all he gets from that remark is the Jack the Ripper reference.] I don't think of it like that. I don't really like evidence or dramatics.