The PES picture is not good, it seems to be a photographed TV-screen, and alot of detail has been lost. The goalkeepers limbs seem to be bled out a bit by the grass color.
The main problem with FIFA pitches seeming smaller is that it takes players less time than usually realistic to move across certain distances, it's not much but players being able to turn 180 in an instant and pursue you, the AI always moving at the exact same pace (full stick-tilt dribble without sprinting) as soon as they receive a pass, and players in general being a bit more responsive than what is realistic, the pitch just seems smaller (or rather, there doesn't seem to be quite enough space).
Same thing with goalkeepers, they can move very quickly sometimes and sometimes jump REALLY far, which will give you the illusion of the goal not being big enough. If they just added more inertia and based response speed, turn speed and other movement speeds on real life, I figure everything would settle in quite nicely with the engine they have.