Strange icon on bottom left

I'm trying to understand that screenshot -- do you have splitscreen turned on? Also, you said tapping it wakes the screen -- so it's visible even when the screen is asleep?
 
I'm trying to understand that screenshot -- do you have splitscreen turned on? Also, you said tapping it wakes the screen -- so it's visible even when the screen is asleep?
It look like button gestures the ability to rotate the screen from good lock module , you can add short cuts to your button navigation or it's the Android auto rotate feature.
 
My husband is a phone noob. And has no idea. He is currently working in USA and I am in Cape town South Africa. That is just the screen shot he sent. Doesn't have time to press on it
 
My husband is a phone noob. And has no idea. He is currently working in USA and I am in Cape town South Africa. That is just the screen shot he sent. Doesn't have time to press on it
Understand but we going need more feedback to figure it out but to me it looks like what I described