I don't get it

lol in a twisted sort of way it does actually. The warping of the mirrors makes sight behind uncomfortable unless there is an object directly along the entire length of the sides as a point-of-reference for the straight and narrow, but the lines and getting out and looking around tells ya if you are crooked or not too even at night. I like my mirrors angled where the horizon or ground is a few inches above the bottom and I can just barely see the wings of the truck and length and height of the trailer. I angle all the other mirrors to see my blind spots and a few other things too.