I personally despise any set parameters, ie; no tree planting 75 feet from a green or whatever the ASGCA norm that was stated above. These sort of norms are inhibiting when it relates to golf course design and more importantly, variety. Sure you don't want to plant large trees near a greensite, but are we seriously pacing off 75 feet? Also, if the tree is on the outside of that bunker is it any less egregious? Will the roots not grow through the path/bunker/green anyway aka; the reverse triple play? I agree with Jon Wiggett, take into context it's relation to the hole and the playing characteristics it presents as well as the agronomic problems it may or may not create. It looks as though the photo is taken from the far left side of the green complex in the rough. I may be mistaken, but how much does it affect play unless you are truly out of position on the hole?
I worked with an older shaper that told me our green was too big on the particular par 5 we were building. He insisted that any par 5 under 525 yards needed to have a 5000 sq. ft. green or it would be too easy and then proceeded to lecture me on green sizes in relation to hole length. I have never forgotten that and will not be told what are the set parameters in any way, it is contrary to interesting, creative design. Also, I kinda like the look of the bunker.
However, to contradict myself, I do remember the small pot bunker on the 9th hole at Valderrama having a large Cork Oak in it and the absurdity of it. If I can remember how to post a pic on here I will.