What the guys suggest is the LEAST most should aim for. Start by (and yes I've seen this) NOT USING YOUR DAMN PHONE DURING EXERCISES. You are not in the moment when you've a 5-kilo / 11 pound plate each side of the leg press and you're showing a buddy a cat video on Facebook.
True mind muscle connection I see our local pro sometimes doing (IFBB/Nabba pro James Llewellyn. He'll be off by himself, completely focused on the very real pain and discomfort of slow protocol leg extensions. He should be thinking about the fibres contracting then stretching, then contracting. He should be thinking about shape and separation and more.
It's a little like a zen moment. The closest I get is during my very heaviest of sets (I'm a strength athlete). Here's an example:
Monday I used a power squat machine (aka v-squat - google either). My top set involved me ending up getting a PT to help me rack as it pushes down so hard it compressed me a little so I can't rack it nicely ha ha. It was 370kg x 7 reps (a bit over 800lbs). The moment I un-rack it it's all I can do to think about moving from a-b for the reps. There's no thought of bills that need paying, work, posting on Elite... you get the picture. Just the reps. That and not breaking my back lol.