On Chinese forums, the original post is the 'first floor' (楼主), so 二楼 is the very first reply. 'Sofa' (沙发) culture around 2005-2015 meant users raced to grab 二楼 on popular threads — an early version of 'first!' culture.
mistakes
In Chinese usage 一楼 is the ground floor, 二楼 the floor above. In British English 'first floor' ≈ Chinese 二楼, but in American English 'second floor' ≈ Chinese 二楼. Be careful when translating.
