Coutinroy wrote:
He told me to so he could show me this xD.


And the name is put to that due to a situation that had happened prior to in the day.

Plus you guys do realise, a Cotton Picker, is a farming job right ???. just to the modern day gets used in different ways. for example

there is a name given to some chinese people called "wang",
Yet in english, we decided to change it's original meaning to be dirty.

Cotton pikin' is also a metaphor within the english language, and Cotton picker is a representation of a machine that automates the harvesting of cotton

Also, i wouldn't believe everything you see on urban dictionary, as ANYONE can go on their and comment a meaning, just like wikipedia.