...
Bring it, punk. Bring the numbers.
The first picture is plain wrong,
why?
There's to much pressure on the lower back, just check out the natural curve of a back, and the structure of the vertebrae , if you bend over, certain vertebrae will be under to much pressure. It's better to use a bench if you want to go flat.
If you do them standing, dorian-yates style is better, a certain degree must be maintained to prevent hernia.
It's safe to say that the first picter isn't a very effective exercise to perform cause there are better alternatives, a regular bench with a barbell is better.