ui: These guys are mathematical researchers. Their job is not to showcase pixel artists, but to showcase their algorithm. And for that reason I think it's actually the right choice for them to choose game sprites. The game sprites are neutral. Game sprites should be well polished, but don't really mean anything outside of the game context, which means the average reader will focus on what the algorithm does. More artistic artwork will likely beg the questions, where is this from, what does it mean? and take away the attention of the thing on display (the algorithm.)
And to continue the neutrality argument, game sprites are pixelated because they needed to be, and were actually usually not even perceived as being pixelated because of the TV screen's blur. It was never part of the aesthetic. Pixel art on the other hand, especially in recent years, is focusing on the pixelation as an aesthetic. It might even be seen as a light insult to the artist to depixelate their art. All of a sudden you have two conscious aesthetic choices that are competing, pixelated or depixelated, and the reader will perhaps not be judging the algorithm just on its technical merits because he may have a bias towards the pixelated aesthetic, if they were using "modern" pixel art as examples.
