"I have a few magic objects from the Ringmaster that you can observe—though it's observation only. I don't want you changing the enchantment on any of them."

Especially considering that one of the magic objects is the creepy wife gem, something that Strange is still worryingly co-dependent about. Still, he's explaining this all in a light tone. Strange trusts Rita. If he tells her not to manipulate the magic on something, he has faith that she won't do so.