The musical act in such talkshows seems to have something of a "break" for the guests, so they do not have to expect to be asked something suddenly by the hosts. These kind of shows often try to reach some interaction between the guests. So during Mark's playing they maybe felt a little like taking a deep breath, have a drink, eat something etc.
I thought he was very well received from the audience, already at the beginning of the show when the guests were announced, there was some excited jubilation noticeable.
He was guest already two times, and as a guest sitting the full two hours (with simultanous dolmetcher in his ear) he seemed somewhat unhappy and not too relaxed. This time, he was more announced as a "top star" and the highlight of the show.
LE