A couple of times recently I read someone referring to the appreciation of an image by questioning what the "cows" would think of it. What is that supposed to mean? It sounds derogatory to me.
I think it refers to the C index Rating. How some people will hurry through the voting process to post an image " like a herd of cows". It's just a little saying that started a while back and looks like it stuck. The hurrying process therefore affects the c ratings at times....Not saying this happens all the time..but I think that it what it is referring to.
I second that /\ and would just add it is no so much meant to be derogatory as is it is an an expression of frustration, both of people who rush through the VB in order to upload and those who leave "nice shot" type comments on everything they view. This is rather lengthy now, but you can find an interesting discussion here. Hope that helps.