One thing Bella has noticed about Mathew is that he is cold, rarely showing his emotions. He rarely smiles, gets angry or shows excitement, and it can get really frustrating if you are trying to get information out of him by reading him. She has gotten nothing so far, he doesn't give anything away.
Which is why she is disturbed at his sudden display of annoyance.
And it can only mean one thing; it means a lot to him that she takes the Alpha position as soon as possible.
But merely thinking about taking such an important position makes her shiver.
She imagines everything going wrong as soon as she takes the position because she doesn't know s**t, and everyone will quickly go from being excited about her presence in the pack to looking at her with disgust because she has failed to delive
