I was baffled by an incorrect narrative I was constructing: The aliens are laser-burning a mutation into the human genome in the first panel [and specifically the Y chromosome]; then battling in an abandoned city with a colonnade; then withdrawing and leaving a different neighborhood intact, because of something they learn in the human/alien dictionary. And for some reason that leads them to misspell their victory message.

…. And then I looked at panel 1 on a different scale.