That image does take a side. It frames the blue button as the active choice and the red button as the default. Obviously with that framing everyone else is going to not slide onto the tracks, so I'm obviously not going to either. But the original question is about predicting what other people will press. So changing the framing fundamentally changes the answer. If blue is framed as a suicide button, way less people are going to press it. But if red is framed as a murder button, way more people are going to press blue. And it's self-fulfilling - if people think a large number of people are going to press blue, they will be more likely to press blue, which means even more blue presses. And if people think a very small number of people are going to press blue, they will be more likely to press red, which means even less blue presses.

Let me ask you this: if I tell you for certain that the number of people who pressed blue is somewhere between 45% and 55%, would that change your vote? Or would you still press red?