You twist the brush itself, so it goes in different shapes. This is number 1:
Twisted all the way to number 2, it squeezes, so it makes the brush shorter, thicker, bristles closer together and holds more product.
This is my result when using the brush all the way stretched out, number 1:
I'm already impressed! This is using it twisted to number 2:
This is my left eye, "the bad one", where my lashes are sparser. But the effect is very visible even from a distance.
All the mascaras I've bought recently have felt too dry, but fortunately this one was not. I felt like the formula was thick and really long lasting too. I like this mascara a lot, and since it seems I'm doing well with them, I'd continue to buy from Bourjois.