mutant-powers
Explanation
The Joke
A girl explains that her father was a powerful mutant (a Cyclops-type figure who could shoot powerful lasers from his eyes), but her mother was a regular human, so she only got "a little of each parent'''s power." She demonstrates by pointing out the red dot on a fence, noting it is hard to see in daylight. She then adds that while it is a cool trick, it does not really affect her life much. Her companion responds: "Actually, you can scarcely imagine the futures you'''ve never contemplated." In the final panel (labeled "Later"), the girl is shown being worshipped, wearing a crown and declaring "I am a living god" -- having apparently realized she can use a low-powered laser pointer from her eyes to dominate a room full of cats.
The Humor
The comic subverts the typical superhero inheritance trope. In X-Men and similar franchises, the child of a powerful mutant would inherit dramatic abilities. Instead, this girl got the genetic equivalent of a laser pointer -- a hilariously underpowered version of her father'''s devastating eye beams. The initial setup makes it seem like the joke is simply about having a lame superpower. But the twist reveals that even the most trivial power can be world-changing in the right context: a permanent, hands-free laser pointer emanating from your eyes would make you an irresistible figure of worship to cats. The companion'''s philosophical comment about "futures you'''ve never contemplated" turns out to be surprisingly literal.
References
The father'''s power is a reference to Cyclops (Scott Summers) from Marvel'''s X-Men, who projects powerful optic blasts from his eyes. The joke about cats chasing laser pointers is rooted in the well-known feline behavior of obsessively tracking small points of light.