...is it sad that was one of the nicest things Kaiba ever said to him? At least verbally?

Probably.

It was a thank-you, and he wasn't one for niceties. Rude and backhanded that it was, that meant he liked it, at least.

Yuugi's cheeks darkened.

Why was his stomach so warm?

"Well, you hate the 'f' word, so...figured I wouldn't use it?"

Even though Yuugi used that word constantly while Kaiba was in a coma. Even though he took pictures of things he thought Kaiba would want to see when he woke up.

"And um. You're welcome. I'm glad you like it."