So that’s a maximum-energy landing test. That means flaps down, but no thrust reversers.
In that test, the plane takes off, climbs, and then comes back around to land at a chosen high landing weight and velocity. It touches down at a speed near the maximum operating landing weight and then the pilots apply full braking. The purpose is to simulate the worst-case kinetic energy the brakes must absorb after a heavy (can’t dump fuel, full cargo), high-speed landing.
If I remember right, it must sit there for a certain number of seconds before the brakes are allowed to catch fire. And they absolutely 100% will catch fire after a landing like that.
A lot of factors matter here (temperature, speed, etc.), but a plane like the 777 should be able to stop in about 4,000 feet.
But it fucks up the brakes, tires, and potentially other things too.