Pivoting = repositioning
Sometimes, there are signs that you need to change direction. This can happen in a company — in which case there are often commercial signs that things need to change, ranging from sudden interest in something that had seemed tangential or minor to the company originally or a clear disinterest in the company’s current direction.
This can also happen in an open source project. If you notice that something that used to be relatively minor about the project is attracting a disproportionate amount of attention, you should pay attention and potentially pivot to focus on that thing.
Most pivots come down to, fundamentally, changing positioning. You notice that you need to pivot — that something is not working. The signs you need to pivot are pretty much the same as the signs that you need to reposition. Figuring out where to pivot to is pretty much identical to figuring out how to best position your project.
Sometimes repositioning is huge, sometimes it’s minor. Same with pivots.
The only difference is that in many cases, you haven’t taken the time to position your project/company well in the first place. Is that really a pivot? Nope. It’s more like trying to figure out which direction you were already headed.