No, they don't, but Mahler's music is essentially serious and melancholic, therefore Tessa's description of it as "colourful, it's really joyful" seems incongruous to me. The choreography is absolutely stunning, and they skated it beautifully, but only Scott's expression was pitched correctly to match the tone of the piece. It felt strange to watch Tessa smiling at the beginning. The facial expressions should interpret the depth of this serious classical symphony throughout. Umbrellas of Cherbourg-light-frothy-romantic-young-love (which I adored) it isn't . This is a far more mature piece of music and style of routine, and both their performances should match it. I hope they do. It will then be a masterpiece.
Gustav Mahler wrote this particular movement as marriage proposal to, then, Alma Schindler. So, it is the love story of the Mahlers.
However, they had personality issues: Gustav was a super artistic, introvert and Alma was totally the opposite... liberal, out-going (especially with artists). Alma never seemed to understand Gustav... At least to me she did not have that kind of depth as a person (Let's give her a break... she was 19 years younger than him). From Gustav's point-of-view, Alma was some sort of fire that he could not quite handle... she left a huge burn mark in his heart, despite of which he could not help but loving her... She was his source of inspiration as well as absolute desperation.
Tessa's smile and her jolly description of the music reminds me so much of Alma Mahler and your uneasy feeling makes so much sense because the music is desperately compelling. It doesn't matter if her expression is too light for the music, because this irony seems the essence of Mahler's later music, especially in the symphonies.