Put an ACO sight on any weapon, aim at the sky during the day NOT looking down the sight, and look for a shadow of sorts, which is the artificial collimation, in the area between the center of the screen and the ACO sight on the weapon. May involve changing the time of day (most of the showcases are around dawn or dusk, not sure about mid-day), some moving around, aiming higher or lower, or rotating the character to see the shadow more clearly.
Also, I've seen the same thing on both my old TN panel monitor as well as my brand new IPS monitor with 32 bit color depth. I did have backlight brightness for both monitors maxed out, so that might make it more noticeable.