One question I’ve always had with the Drake equation is if it needs another line for scale. That we are roughly the same size, and experience time at roughly t

One question I’ve always had with the Drake equation is if it needs another line for scale. That we are roughly the same size, and experience time at roughly the same rate. Would we notice an alien civilization sending a signal with a small message over the course of hundreds of years, at a bit a century frequency? Would we recognize each other as life if one is the size of a galaxy or the size of an atom?