It could be a game like terraria or minecraft or factorio, or a game map editor, or a middle school hand calculator, or spreadsheets, or an automatic hotkey or macro app, or anything that is at all flexible or extensible. Of course several of these wrap real programming languages but it's not obvious at first especially if you never did programming. There are so many ways, and it's likely that embryonic hackers will come across something like this and use it to make silly program-like experiments and tinkering before they learn how to program. Or at least that was true earlier. Maybe replacement of computers with phones has changed it, I don't know.
So your distinction is that hackers gravitate towards extensions of turing completeness (i.e. code representations) as opposed to mechanical systems like basic engines and or machines?
This seems mostly true in my personal life. As a hacker, it explains my 5 year obsession with minecraft and gmod in my teens. I got deep into gmod e2 and then actionscript3 (RIP). It also explains why some mechanically gifted people I know don't "get" the flexibility of code, despite their intuition for systems. I think it takes a certain conviction to modify and extend abstract systems. Problem diagnosis is not obvious and can be very frustrating. But the dopamine hit of seeing things work together is enough to keep me going.
Overall, my hacker foundation is built on a never-ending loop of frustration and desire. Frustrated things aren't working with a desire to make things happen. I didn't program professionally until recently, but I instantly understood the mentality. I'm grateful for the wisdom my career has given me to pursue it.
> "So your distinction is that hackers gravitate towards extensions of turing completeness (i.e. code representations) as opposed to mechanical systems like basic engines and or machines?"
Oh I didn't mean that at all, they could like engines too or even more, just they aren't turing complete (unless you mean like babbage machines or that crab gate machine which I assume most children wouldn't create or have access to). I meant that usually these proto-hackers as children at some point will have accidentally found a turing-complete thing and played with it when they were children before they learned programming officially, even if they like other things more. Then the moment "the first step from being a tinkerer to being a skilled craftman" would come when they learn that programming is a thing and they find it's actually so much easier than the convoluted logic systems they were making themselves.