Although the voice-over in this moment is vague, it’s rather apparent that something happened to Sheila in the prison camps that continues to haunt her. What’s more, it seems likely that she has kept this traumatic experience a secret from Bridie, since she only thinks about it once Bridie leaves. Lastly, the fact that this memory blossoms in her mind when she stares at a shoe-horn—an object associated with Bridie—indicates that whatever happened must have something to do with her friend. Given that the two women have just had an argument about self-sacrifice, this is an important moment, as astute audience members will surely intuit that Sheila has done something for Bridie that remains unspoken.