SB is the abbreviation of a swearing slang (sh m: b: and) in China.
It is ironic and contemptuous of the IQ of the landlord to express disapproval of the poster's point of view or dissatisfaction with the poster's character, which has a certain uncivilized tendency. It is suitable for people who publish Martian posts, and it also expresses great dissatisfaction with the landlord's posts or posts that belong to brain-dead posts.
Although Lanzhou sesame seed cake is a swear word, it is relatively euphemistic compared with directly scolding LZSB.
However, this sentence has another meaning, because LZ can also be extended to Laozi (that is, the poster himself), so use it with caution.