Why does my Macbook Pro screen go dark when my hand covers the top left corner by the keyboard & screen?

I have the oddest situation with my current Macbook Pro laptop. This doesn't cause any harm to my laptop, and it honestly doesn't bother me in the slightest but I've never seen anything like it before and am curious to find out why it's happening.

Whenever I cover the top left corner of my laptop, usually with my hand when I'm opening the lid some more, where the screen connects to the keyboard (the point at which it bends / folds in, right by the charging port), the screen goes to sleep. As soon as I move my hand, the screen returns and I get the "Logged In" noise, that you would typically hear if you opened up/logged into the Messages application, for example. I do not disconnect from any of my network connections when this happens and there's absolutely zero effect on my laptop otherwise.

I work a medium-sized office where we all work on Macbook Pro's and not a single other person's laptop does this, from what I've been able to find. I've also not found anything written about this online.

Again, I'm posting just out of sheer curiosity but hoping that someone else might have experienced something similar, or knows why why this might be happening?

Here's an example video of this happening: Dropbox - Laptop Screen Issue.MOV

Edit: this does not have anything to do with any of the side ports on the left, or the charging port specifically. My hand needs to literally be covering the full corner (part of the keyboard, part of the screen) in order for the screen to go black.