ha-2
Explanation
This comic features Superman (or a Superman-like superhero).
In the first panel, a villain is laughing maniacally ("HAHAHAHAHA") while committing some crime or causing mayhem, with people in danger.
In the second panel, a bystander confronts the superhero: "You could've saved them if you'd just kept your suit on and done your whooshing!" The superhero responds: "I guess in fairness you aren't referring to my being brave."
The joke plays on the classic Superman trope of Clark Kent needing to find a phone booth or private spot to change into his costume before saving people. The bystander is pointing out that the hero wasted critical time changing clothes -- people died because of the costume change routine. The hero's response suggests he interprets "kept your suit on" as a comment about bravery (keeping your suit on = staying in the fight), when really the bystander is being very literal: just keep wearing the super-suit under your clothes and stop wasting time with the dramatic costume change.
This satirizes one of the oldest and most parodied conventions in superhero fiction -- the impractical secret identity maintenance that costs lives. SMBC frequently takes well-known fictional tropes and examines the logical consequences that the original stories conveniently ignore.