Fractal refers to replication of identical elements in ever smaller sizes starting from a single base shape.
All the pivoting arrangements of the vice segments are the same shape. Each little segment moves independently, as each larger segment does, so the vice jaws are true fractal! 2 to the 4th power.
Mandelbrot basically formalised the mathematics to establish the general solution and demonstrate the capability of infinite expansion.
Infinite replication of ever smaller elements doesn't actually have to refer to identical shapes but the maths is more than a little challenging rendering the concept pretty much impractical in an analytical sense.
Clive