imagine 在此为及物动词，其后的 being without it 为动名词短语，作 imagine 的宾语。
不能理解为只是 being 作宾语。又如下面的各句，宾语是整个动名词短语，而不只是单个的动名词：
He likes reading stories. 他喜欢读故事。
Have you finished cleaning the kitchen? 你厨房打扫完了吗？
Try to imagine being on the moon. 设法想象你是在月球上。
I really object to being charged for parking. 我非常反对收停车费。
