A seat at the window

An original fiction passage set in the nineteenth century.

Miss Arden chose the chair facing the street. She said the light was better there for reading, although her book remained unopened. Every passing carriage drew her attention. Once, she rose so quickly that the cushion fell to the floor. It was only the baker. She resumed her seat, and expectation settled over her again like an uncomfortable shawl. Her companion politely discussed the weather.

Identify the phrase which suggests that waiting makes Miss Arden uneasy.