It's my 5th time rewatching this masterpiece, and I've found some interesting details: - Bocchi opens her eyes at 0:15, but her consciousness does not return until 5:05. (Notice that the scenes are the same at 0:15 and 5:05.) This tells us that from 0:15 to 5:05, it is purely Bocchi's flashback interweaved with her imaginations, which explains why the narration style feels so much like a flowing stream of conciousness. - Bocchi facing the opposite from the audience from 5:14 to 5:18 parallels with the same image at 5:27. The contrast here between the realities and her imagination is so strong that it made me feel so sad.
