Empathy
Explanation
The Joke
A character explains that empathy is what makes us human. Another character points out that empathy is highly selective — we feel deep empathy for one photogenic child but almost none for thousands of statistical deaths. Empathy scales terribly with numbers, is biased toward people who look like us, and can be weaponized to manipulate.
The first character says they still think empathy is beautiful. The second character asks if they'd feel the same way about a cognitive mechanism that made them care more about cute puppies than starving children.
The Humor
The comic complicates the feel-good notion that empathy is an uncomplicated moral virtue. While empathy is central to human morality, it's also unreliable, biased, and easily manipulated. The comedy comes from the tension between the emotional appeal of empathy and its measurable shortcomings as a guide to moral action.
Context
This argument is made at length in Paul Bloom's book Against Empathy: The Case for Rational Compassion. Bloom argues that empathy (as emotional identification) is a poor guide to ethics compared to rational compassion (caring about outcomes regardless of emotional resonance). Effective altruists make a similar point: we should help where we can do the most good, not where we feel the strongest emotional pull.