The trolly problem doesn’t apply to Gaza and the commenter in the image isn’t really criticizing the image right.
In the trolly problem, throwing the lever is effectively choosing who gets to die. That’s the philosophical choice: you become the person choosing which lives are valuable. It’s not just about being a murderer or a bystander. Even by noticing the lever, your inaction is a choice. IMHO, pretending you can remain a bystander by not throwing the lever is just moralizing your lack of action. The real philosophical question in the trolly problem is about human life and how to even measure it. Is the problem the same if the single person is a mother of three, and the five people on the other track are proven murderers/rapists? Should you throw the lever if you don’t know the people on the track?
The trolly image in the meme doesn’t even make sense. You’d have to draw the Palestinian man across both tracks to make it match the real life situation. It has been demonstrated that neither party is interested in saving those lives. (That doesn’t mean it’s not worth pressuring Biden)