Ten's eyes follow himself how do you know it's inconsequential? Just because they're both outside of time doesn't mean a thing! The TARDIS changes your brain, self, how do you know they don't remember what happens here?

When his other self-states that the interest isn't in Four's future, Ten does seem to loosen up and not appear so dire.

There's not even a wince when Ten's nose is tapped, just get on it with self, "Alright."