Mariah Carey lived up to her divalicious reputation when she served as a guest mentor on American Idol last week. Tops on the “Touch My Body” singer’s list of demands was that the show’s crew angle the set’s lighting so that she was “positioned perfectly at all times.”

“We had to reshoot one of the questions,” one cameraman told Fox Entertainment News. “I had to change the lighting and alter the position and do it again because we went off angle slightly. She has a director of photography with her at all times and can only be shot from the waist up.”

And her Idol outing wasn’t the only public appearance where Mariah created a stink last week:

She did lose quite a few fans on Thursday night when she decided to turn up two hours late to an album-signing at Universal City, Fox reports.

“She strolled in with sunglasses on when it was nighttime and by that point a lot of people got fed up and had left,” says one photographer. “It was ridiculous.”