OK, in front of a computer and not at work. yay!
So, there's a whole lot of stuff going on with that car that's sort of "cheating" - both mechanical and cosmetically. (And I apologise that some of this is a rehash of points already raised.
It's wide. Like REALLY wide. Width cheats flex because it puts the contact patch further away from the springs.
It has heavy axles, wheels and tyres, and no (front) spring clamps. This pulls the spring pack apart on droop. This over cambers the main leaf which leads to very high loads and risk of bending on the main leaf. Imagine the axle wrapping if the car is hopping on an obstacle - that's putting all that twisting load onto the main leaf only.
The photos are of the drooped front wheel side, and as has been pointed out, the compressed rear wheel isn't compressing very far. I'd be interested to see the compressed wheel on the front. I don't think its flexing as much (measured as degrees difference between the axle and the chassis) as it looks - so it's an bit of an optical illusion.
Compare the photo at ride height to the photo at droop. at ride height the top of the tyre is roughly level with the bottom of the sill. At full droop the tyre looks to be ~175mm or so below the sill or so. That's nothing special.
And then there's the whole SPOA thing where SPOA cars are somehow immune from Young's modulus. Steel has a working range and once that's exceeded it fails. Stock leaf suspension is designed around this working range. No bumpstops will invert the springs on full compression which is a recipe for very short spring life, so it's a short term "solution". The springs typically break where the main leaf meets the secondary.
For reference, here's a RUF SPUA car with bumpstops with a "2" BL and 35's, so it's at least 7" lower than that pile and can still put the tyre well below the sill on flex.

And here's when it was on 33's
