Trivia: Audrey Landers is not seen in wide shots of the entire cast while dancing because she was an inexperienced dancer.
Trivia: In the original Broadway production, Cassie didn't get the job. After a few performances, they changed it and since then have gotten standing ovations.
Answer: The problem is she's "too good" of a dancer. The audition is for a chorus line where the dancers have to perform uniformly and as one unified group. She keeps doing the extra moves and gestures, making herself standout from the others, which is exactly what Zach does not want. He even tells her that she's too good of a dancer to be in a chorus line. She's talented as a lead or solo, but she needs this job. She has to continually restrain herself to blend in.
raywest ★