This isn't THAT much cleavage, so it's fine without the need for a NSFW banner. Something that might need it though would be something like a string bikini barely covering some massive mammaries.

Mmm, I don't know. I like this one, but it has this weird ''she's hiding something from us'' feel to it.

The pony version, on the other hand, is more of a ''she enjoys watching the CMC be happy'' kind of face.