For the shart basically means the same as "for the suck", or "that sucks", however the imagry that goes along with the term "shart" adds insult to injury to make it a more effecient term to describe something unwanted, or a bad experience.
brandon: OMG i totally
tried to fart but pooped my pants at work the other day
me: dude, thats for the shart, literally.
brandon: dude, that movie was pretty bad, except for the scene with tubgirl
me: yea, it was for the shart...for sure!