I wondered that also. The reactions to things felt flat. Then again, she's a very flat character. Her reaction to being turned into a rabbit at the end was like "huh..Mumford? Can you come back?" Whereas Kermit is far more frantic and/or defeated in similar skits.With segments like this, I wonder if the video image was pre-recorded or if it was being done live on the set (like the Leslie Mostly set is in one part of the studio, the guests' home in another part, and both parts were being recorded at the exact same time). I didn't think that was how things like this could be done... I remember years ago people told me that the "Two-Headed Monster Co-Operation" segment had both the street scenes and Two-Headed Monster segments done at the same time, and I didn't think that could be possible, but then I saw behind-the-scenes footage that showed an away-from-the-street set by the street set, so I guess it was possible.
It's been stated that Leslie Mostly's delivery and personality could be due to the fact that the interviews were done by satellite. Somebody here said that her interview with Grover had Leslie Mostly in person with Grover. I wonder if she had better delivery in that segment. It would also be interesting to see if she ever appeared in any street scenes (seems like a lot of unlikely "skit characters" made appearances in street stories at some point). Seems Leslie has just a little less personality than Warren Wolf.
I've also noticed that the satellite TV hook up camera was done with green screen, and the camera moves make it obvious. There seems to be some weird glitch, like a blue blob where the smoke should be when he exits.