I think Albon described it really well a while back. Think of the equivalent in gaming terms of playing an FPS with your mouse sensitivity turned all the way to maximum. That's how sharp Max likes his cars.

If it's super on the nose, it should be very high performance under breaking and the rear end will want to slide out. That makes it super unstable feeling.

I think max is probably leagues above most others with accepting that and working it to his advantage. If it makes you uneasy you probably just don't brake hard or push super hard

I can add: usually a high rake angle, a bit less rear mechanical grip (but more aero grip), which means the car feels even more different at lower speeds than higher. Really light rear ends are very fast and good on tire wear when driven perfectly, but unforgiving

That's my armchair understanding