Premise 1: Geeks don't wear (Dockers) pants
Premise 2: You don't want to be a geek
Conclusion: You should wear Dockers Pants
The unstated premise is the second premise. This is the weaker premise because some people don't mind being geeks and enjoy not wearing pants.
One of the fallacies used is ad populum. The commercial appeals to the fact that men don't want to be geeks and they want to be manly and accepted. Therefore they should wear Dockers pants.