...Of course, butterfly therapy in real life might be a bit horrifying, since they aren't as cute as in MLP, looking like most bugs. The wings on butterflies are really the only thing pretty about them I guess.
That was an interesting concept they explored in "Too Many Pinkie Pies" Who knew butterflies could make somepony so...peaceful. Usually you'd be too busy trying to catch 'em or get a closer look. Sorry, I'm rambling. This is a great piece. ^^
It's actually rather complicated but brilliantly subtle. In some cultures, butterflies represent the soul that has departed from the body after death. While the uninitiated think that butterfly therapy works by just having a bunch of pretty butterflies flitting about you, it's really more of a spiritual communion with those that have gone before you, such as close friends and family. The swarm of butterflies in front of your eyes is rather hypnotic, placing you in a trance, and it's in that state of mind where memories of your departed loved ones are brought to the fore. The whole point of lying in a coffin-like couch is basically trying to meet the departed halfway, thus making this connection easier to obtain.
Based on the underlying principles of butterfly therapy, you might think that it would be a rather morbid and depressing thing to go through, but it's surprisingly uplifting. It does help if you have loved ones that you have a lot of happy memories of, so butterfly therapy is not for everyone.