This question could be answered from different angles. From the plot of the novel, Zhang Xiao's time travel to the Qing Dynasty might just be a dream because the novel did not describe the process in detail. However, if we look at it from a realistic point of view, we need to consider many factors. If we assume that Zhang Xiao's time travel to the Qing Dynasty was just a dream, then she might feel confused and uneasy because she did not know if this world really existed or if she had really returned to her own era. She may experience many strange dreams and hallucinations, which may cause her to be physically and mentally exhausted. If we assume that Zhang Xiao's time travel to the Qing Dynasty is real, then she may find that this world is different from what she saw in the novel. She may meet many different characters and experience many different events. She might find herself unable to adapt to this era and might face many difficulties and challenges. Therefore, we can conclude that Zhang Xiao's time travel to the Qing Dynasty may be a dream or it may be real, but in either case, she will experience many different experiences and challenges.