Mariah's comment was, I'm willing to bet, not about Leona in particular. It was about people constantly saying to her "howd you feel about X?
They're you're replacement, according to the critics."
It's like saying "you're over. How do you feel about your replacement?".
I'm in no doubt that she's heard Leona. She probably doesn't know how big a fan she is though, or how "nice"* she is, Mariah is probably
more insulted by the insinuation that she's being replaced.
The question makes Mariah look old, that's why she sounded annoyed. You could have replaced Leona with any name, and you'd have gotten the same
reaction.
*BTW Leona isn't really as "nice" as she's made out to be. She flies with British Airways, and my boyfriend works in first class as cabin
crew. He's had the pleasure of serving her and from what I've heard she's getting into the diva thing quite quickly LOL