laser-2
Explanation
This comic presents a scientist explaining to an audience (possibly government officials or investors) that for about 4 trillion dollars, we could construct an interstellar-scale laser system powerful enough to direct energy beams at distant objects from Earth. By choosing a precise surface target, we could either heat or illuminate any object, effectively giving humanity the ability to "mark any object in the Milky Way with an up or down state."
Someone in the audience then asks the practical question: "So maybe we could use this to communicate with aliens or something?" The presenter responds: "Why would you want to do that? What would it even be about?"
In the final panel, it becomes clear the real motivation: "We can run Doom on the galaxy." The scientists want to use star systems as pixels to play the 1993 video game Doom at a galactic scale.
The comic plays on the long-running internet joke that any sufficiently complex system can (and should) be made to run Doom — people have run it on pregnancy tests, ATMs, and other absurd hardware. Here, the joke is escalated to its ultimate extreme: using the entire Milky Way galaxy as a display. It also satirizes how scientists sometimes pursue enormously expensive projects not for practical reasons but for the sheer joy of doing something technically impressive and utterly pointless. The dismissal of alien communication as boring compared to running Doom captures a certain flavor of engineering culture perfectly.