Should junkrat jump on top of his mine or walk on top of it?

To "better" use concussion mine to jump?

What does better mean?

I don't know. What method the pro uses? What's the plus and minus?

Presumably higher I suppose.

From personal experience, I normally just detonate and jump at the same time. You just want to be really close to the mine and in the air with your momentum from the jump helping propel you upwards. The closer to the mine you are, the more knockback you receive. I kind of view it from the TF2 perspective from rocket jumping and trying to jump at the exact same time you fire a rocket at your feet.

Some good things about going higher is that you can possibly get a nice bombing run, what I like to call shooting Junkrat's grenades in the air while enemies are under you, and disrupt enemies on important objectives. Some bad things are that you are in the air for a decent amount of time and a good Widowmaker can easily pick you off. It's all a balancing act of what you need in the current situation. Maybe you need a quick horizontal movement rather than a big jump. It all takes a little bit of practice and knowledge for what you need.

A good jump in my view is just a jump that gets you where you need to go while taking not too much time for someone to pick you off as you reach your peak in the air.

While using Junkrat's concussion mine, it is better to jump then detonate it based on how you want to move. If you want to get good height as well as move forward, your best bet would be to jump and detonate the bomb as you are still moving up or as you reach the peak of your jump. The reason for this is how much Junkrat's own momentum effects his explosion jump. In custom games, I've found that it is hard to stay in the air with infinite mines because of his momentum moving down as you begin to fall, but this can also be used to move to the side and still be close to the ground so that you may get your movement back quicker than usual. What I'm saying is that the momentum and placement of your jump is the factor that will help to determine whether you should use or mine in a jump or not.

The only source I have is my understanding of the game after becoming a Junkrat main.