Resistors soldered 1cm off board
The resistors are spaced away from the PC Board so as to allow better cooling. 

One side benefit of doing this is that heat damage to the PCB is reduced or eliminated. 

It is common to see discolored circuit board under and around resistors that run hot.  Spacing the resistor away from the board both helps keep the resistor cool as well as minimizing board discoloration and damage.