Why do professional chess players point at the pieces with a middle finger? I've recently heard and then actually started to notice more and more that professional chess players tend to use a middle finger when pointing at pieces on the board like in this Anand vs Caruana game during the Sinquefield Cup 2017:


(source)

I am wondering, why is it happening?

Note: this is a genuine question, I am not trying to offend or make fun of anything or anyone here.
When they're analyzing at a rapid pace, they tend to only need the thumb and index finger to pick up pieces and move them. Using the middle finger as well doesn't really help. So since that finger is freed up, they can use it to point (especially because pointing with the 4th finger or pinkie is awkward).

Or they subconsciously despise each other.