Brilliant Sy Parrish's life is dull. Now, we've all seen dull people before, but with Sy, it's painfully dull. Take the song, "I'm Blue" by Eiffel 65 and substitute the word "dull", and you have Sy's life. Dull, sad, and lonely.
That is, Sy's life away from the one-hour photo stand at the SavMart. There he comes alive, and is truly master of his domain. And there we learn to love him.
Mark's and Robin's work in creating this character is nothing short of brilliant. You truly feel for him, and, knowing that in the end he's going to do something the detective describes as "not pretty", all the way through the film you find yourself thinking, "Oh, come on, Sy! Don't do what I think you're going to do!"
And the revelation at the end is absolutely spot-on. With those few sentences, the entire film, and Sy's entire life suddenly pop into focus, and we understand why Sy's life is dull, and why he's lonely, and even why he took the job he did. Absolutely, totally brilliant.
I put off seeing this film for a long time, as I had seen "Insomnia" and didn't care for it, and thought this would be the same sort of character. Far from it!
Oh, by the way, Mark -- I saw the riderless horse as symbolizing futility and pointlessness, like Sy's life. It's interesting, the different interpretations of things!