niiiice
Explanation
The comic shows two people walking on a street. One says: "I've been playing a game where I assign numerical values to letters based on their position in the alphabet, then I check to see if they sum to interesting numbers." The other person responds: "NIIIICCCEE."
The joke operates on two levels simultaneously. On the surface, the second person appears to be reacting with the slang expression "nice" (drawn out for emphasis as "niiiicccee") to indicate they find the game cool or interesting. But given the context of the conversation -- about assigning numerical values to letters -- their response is also a demonstration of the game itself. The word "NIIIICCCEE" is specifically spelled with repeated letters, suggesting the speaker has calculated the letter values and is noting that this particular string of characters sums to an "interesting number."
The comic's title, "niiiice," reinforces this dual meaning. It's a self-referential joke: the response works as both a casual social reaction and as a participant engaging with the exact game being described. The humor also plays on the nerdiness of the hobby -- gematria-style numerological games with letters are an extremely niche interest, and the idea that someone would respond to hearing about it by immediately and enthusiastically playing along (rather than, say, walking away) is endearing and funny.