First of all, the magic of drinking coffee from the mirror, if you think about it carefully, you will find that it is actually a mirror. This is a special mirror, which is unique in absorbing part of the light and reflecting part of it. If the mirror is regarded as a high-resolution display screen, what the magic wants to present can be made in the program in the mirror in advance. As for Liu Qian's real coffee, it is actually due to the reflection of light, and what the audience sees is only what the mirror (display screen) "plays". That's why Liu Qian didn't spit out the coffee he drank.
In the second trick, Liu Qian wrote his name on the card. When he looked in the mirror, the card turned into reverse writing. This magic trick is actually very simple. The problem lies in the card. Liu Qian put the card with the name on the reverse side in advance, then pasted a very thin opaque card of the same size, and then Liu Qian wrote his name in front of everyone. After looking in the mirror, Liu Qian took advantage of the opportunity to talk with the audience and quickly took down the thin card on the top and stuffed it into his sleeve.
The third trick, a woman's hand appeared in the mirror, holding a snack in her hand. The key to this magic lies in the mirror and the space behind it (essentially a multidimensional space). One thing is certain, there must be a man behind the mirror, but the question is where is that man hiding? As I said just now, there is an artificial space behind the mirror, but how is this multidimensional space made? This will be summarized as the role of advanced technology. I remember in a magic show in America, people disappeared out of thin air in full view. The key to the problem lies in the difference between the special effects of light and vision. Liu Qian's magic also uses this principle. One thing to note is that photographers only shoot from one angle. Why? Because a multidimensional space is bound to have a gap, and this gap is right behind the mirror. Because people can't look behind the mirror, they can't see the woman hiding in the multidimensional space behind the mirror.