|Gerald Ford at Univ. of Michigan (1933)|
If you’re copying and reproducing the ad without authorization it’s an infringement. Of course, there's always the "Can we get away with this?" approach. That is, how likely is it that the advertiser will clamp down on reproductions especially when the whole point of making the ad is to maximize exposure?
Fair use. Alternatively, if the advertiser complained, you might be able to succeed with a fair use argument. That is, you’re using the ad for purposes of commentary. Alas, that would be an argument you’d have to make in court and we doubt you want to do that.
Ask for permission. If your comments are unfavorable and you're concerned about a backlash, or if your website is on the prudent side (and worried about liability), ask for permission. Many super bowl advertisers are happy to say "okay" so you may be able to obtain authorization from the owner (either the ad agency or the advertiser). And, of course, be careful when you use the special words "Super Bowl."
P.S. Your other legal questions about the big game are all answered here!