"Become yourself", working hard for it. They could say that Flowey was feeling Determined again but that's probably a poor joke. Frisk could be mean but they weren't about to kick someone while they're down and trying their best to get back up.

So...determined - lower case. They smile anyway. There's also a key word there too.

"Your contract?"

Did someone make Flowey fill out something to get 'himself' back? Is that how things worked here?