I don't think that's an issue with the surface. It's most likely an issue from the source content. You can have the most beautiful of all screens but if the source material is crap, it's going to look like crap. It's most likely the nfl.com video feed or youtube video feed.
hopefully these two images show the pixilation. The connection i noticed fluctuated above and below 3mbps. another thing i tested was speed, on my phone i consistently get 19 -25mbps but on surface it can be 1 - 6 mbps after sleep mode ands restart gets it to higher connection speed. Could be a connection issue for this piece.