Commercials for beer reinforce multiple stereotypes of what American men are supposed to enjoy. The first, of course, is beer. In some commercials for light beer, the man is considered not manly if he settles for a beer that is not from the brand that is being advertised. In one commercial a man is shown wearing women's jeans and in another he is shown hiking in the mountains with a knapsack. These two commercials believe that men are supposed to enjoy beer of a certain kind or they are not manly.
Another stereotype that these commercials reinforce is that men enjoy watching sports, specifically football. Many beer commercials are centered on groups of men gathered around the TV watching football while drinking their beer. It is reinforcing the belief that to be manly, you have to enjoy watching football. Another way that these commercials reinforce this stereotype is that beer commercials are only on during sports games.