What does your mother mean by selling beer in Qingdao?

The meaning of this sentence may be used to swear, which means that your mother sells beer. Your mother sells beer in Qingdao. But it may also mean literally that my mother sells beer in Qingdao, depending on the situation. If two people quarrel and say such things, it is likely to be swearing.

However, some people use it to express their feelings, such as: "Mom sells criticism, how can this (game) be played like this?" "I have a saying that my mother sells criticism and I don't know when to say it."

If you don't have an object, you are talking about yourself, which is equivalent to a mantra. Of course, talking too much must mean that this person is vulgar.