Final answer:
The use of 'vaguely' indicates Ponyboy's detached or preoccupied emotional state, as he only fleetingly acknowledges Dally's distress without deep consideration.
Step-by-step explanation:
The use of the word "vaguely" suggests that Ponyboy is in a somewhat disconnected or distracted emotional state. He is aware of Dally's reaction to a troubling situation but does not fully engage with the curiosity or concern that might typically arise. Instead, he acknowledges Dally's distress only fleetingly and without deep consideration. This indicates that Ponyboy may be preoccupied with his own thoughts or emotions, unable to fully process or react to the events unfolding around him. The term "vaguely" underscores a sense of detachment or a lack of full attention to the details of the situation.