Really? Because I, as a dancer myself, saw the opposite. Alena knows to be more subtle with her movements and make the somewhat ridiculous choreography less so. Look first at Alena and then at Anna; Alena's dance looks more sleek and modern. She understands the highs and lows of the beats and choreography. Meanwhile, Anna is all ATTACK. She's less subtle and emphasizes every movement, to the point that it is looks almost laughable? She is obviously the most eager one though.
I'd say that Anna's ATTACK style actually fits the choreo style, though. If she was going ATTACK on something more soft and lyrical I'd get you, but imo her aggressive movements fit the harsh, weird music very well. And she seemed to know the combo best, she never looked over at anyone and never hesitated between counts, not even once. I am also a dancer who's taken similar classes (I'm not sure if there's another name for the genre, but our teacher always called it quirk jazz) and we were always encouraged to look more like Anna and to throw elegance and prettiness out the window - save that for the contemporary class later.
(I am of course no expert on this style and can't speak for it, I'm just a random girl who took classes at my studio, but I just wanted to say that I for one was taught that it isn't supposed to look sleek or pretty or graceful, at all.)
Alena also did very well, she just has a different style (more elegant and less hard-hitting) that doesn't necessarily fit Zheleznyakov's abstract quirk jazz choreo all the time. As people have already said further up, she would shine more in a lyrical or soft contemporary dance, but I guess the point of their dance classes might be to push them out of their comfort zones, so that might defeat the purpose.
Sasha, who was doing aerobics instead of dancing, was way more subtle than Alyona.
Anna he's kind of understated because she's not as beautiful a skater as aliona is and she's not as spectacular a jumper as Sasha is. But she is excellent at both.