When Holly is shown sketching out costumes for the performance, the top of the sketch paper says "Mistletone's" when the name for the group is not decided until later in the film, at the bar after a rehearsal.
Marcy tells Holly to decide if she wants to join the SnowBelles and says you take the night to let it sink in and meet at the church Monday morning. But at the Office Christmas Party- Holly says she needs to talk to them about the audition tomorrow.
When Holly falls out of the shower after the water turns cold, she stands up wrapped in the shower curtain. Her hair is dry and she is wearing lipstick, eye shadow and blusher.