“爬” means “to climb,” and “楼” is short for “楼梯,” which means “stairs.” Chinese netizens use the term to refer to the scenario where a person has missed the previous discussions in a WeChat group or at a forum, and has to roll the screen up to check out earlier comments. As people’s comments build up like a tower on the screen, the term “stairs climbing” is used.
Tóngxuéqún lǐ yǒu ge tèbié rèliè de tǎolùn，nǐ kàndào le ma？
There is a very heated discussion going on in our classmates’ WeChat group. Have you noticed?
Jīntiān yīzhí hěn máng，děng zhōngwǔ chīfàn de shíhòu wǒ qù pálǒu。
I’ve been super busy today. I’ll check out the earlier comments at lunchtime.