In another, more recent 9/11 strip, Nate, Teddy, and Francis build the Twin Towers out of sand and just stand around, silently paying their honors. Doubles as a TearJerker because earlier, Randy saw them in the early stage of building it, not knowing what it is, and threatened to knock it down.
So, this one chess tournament. In the previous chess tournament, Nate was in a slump because he learned Artur had let him win in a chess game. This one, he's ready to go. There's something heartwarming about Nate, who normally when presented with the possibility of being beat, makes excuses and just generally beats around the bush, accepting the fact that he can be outdone, but still trying his best.
Could also be seen as a slight TearJerker, but when Nate more or less lets Artur date Jenny. Word reaches Nate that Jenny wishes to see him in the library. Assuming a confession, he goes, only to find out she wants him to deliver a confession to Artur, the nice boy that Nate has a one-sided rivalry with. Initially, he opposes, though she convinces him to do so. When doing so, it occurs to him he could throw it away and no one would be the wiser, but doesn't and delivers it. Not only that, he makes himself explain the note to him and gives Artur to pursue her, Artur not doing so during a sooner period to spare Nate's feelings. This shows that Nate does view Artur as a friend and establishes him as a good person.