Pulse shape feature changes the power of the laser beam during each individual shot.  For instance of a pole shape that tapers down like so.  First off if I use 200 volts in six milliseconds the power at the beginning is going to be 200 volts.  But well halfway through it, it is going to go down to 160 volts then 120 volts then 80 volts and finally 40 volts of power.  Right before the beam turns off.  The less power in the shape the further the torch is away from the piece.  So with my slant down shape, it's like I'm pulling the torch away slowly.  This is useful for metals that crack when cooled down too fast like 950 palladium or some white gold.  If you see a crack in your weld you're getting heat tears and should be using a longer slope.  Setting the pole shape to fifty percent effectively halves the voltage making it easier work on lower method temperatures like lead.  So say for instance with the ramp up and down shape, so it's starting off at a lower power raising up to a very high temperature melting the piece and then letting it slowly cool down.  And you can adjust this let's will be tapping on any of these to make the curve more gentle.