The Hotech reflective mirrors are flat translucent mirrors with a paper target glued on the back face. They have two functions.
They reflect the laser beams back to the Hotech board.
The beams paint a target on the back helping with centering and collimation.
One is placed at the back focus of the telescope and the other one in front of the hyperstar. So in effect these mirrors are placed at the various focus points in the light path.