rage against what?

I took this pic with my old sony ericsson W800 back in the year of 2010 at Pusuk Forest, North Lombok during my duty as a cameraman. Wild monkey always hungry on the side of the road waiting for people to feed them from inside their cars.

By any chances this alpha got my attention, just follow it for couple minutes and BOOM! I snap this pic.

And I wonder what this alpha rage against?