In the second act, it is the job of the Picador to further weaken the neck of the bull.
A brave bull will attack the horse without hesitation.
The Picador usually pics the bull twice, but sometimes the matador will allow only one pic, so as to not weaken the bull too much.
He may feel that he can work with a lively bull,or if the bull isn't lively he might want to get as much out of it as possible