Algodoo

A demonstrative scene for XRay. It shows what e.normal represents during onLaserHit/onHitByLaser.

The purple laser orbit's the shape and relays the point of impact and e.normal via scene.my.variable to the green laser.
The green laser then positions itself on the point of impact and takes the form of the e.normal vector.
As one can quickly see, the laser always stands perpendicularly on the surface, exactly halfway between the purple laser before and after reflection.
It's length is always 1 due to the normal vector being, true to it's name, normalized. In fact, the mathematical term "normal" usually refers to a perpendicular vector on a line or surface, with length 1.

In summary, e.normal always represents the way "away" of the point of incident, be it laser hit or collision, always perpendicular to the surface in question.