This man is performing a competition style benchpress
Pay attention to the arch in his back. Only the bottom of his butt,
and tops of his shoulders and traps are in contact with the bench. He is
using his legs to drive his shoulders into the bench even harder. The arch
he is using utilizes the pecs to their fullest advantage. It also works
with his wide grip to shorten the range of motion in getting the bar from
his chest to the locked out position. One should "pinch" the shoulder blades
together while setting up for the competition benchpress. This keeps more
of the shoulder in actual contact with the bench, giving it something to
push off with, which transfers more of one's effort into movement of the
bar. Pinching the shoulder blades together while setting up also keeps
one much tighter for the push.
The elbows should be "tucked" a bit more allowing the bar to touch low
on the chest. From there the bar should travel up in as straight of line
as possible.
Remember this is for the competition benchpress. The idea of a competition
benchpress is NOT to build an optimum physique, but to do the most weight
one possibly can for one repetition.