judging from your photostream, this came off as completely unexpected from you lol. that gets you a fav. from me. ;p
back to the subject, the isolation, strongly reinforced by the seemingly empty bart train does wonders for this, as well as the centering of the photo. the presence of the lone legs up on top can be debated either as an unwanted element of the photo or a tolerable one. I can't tell.
Either way, the photo is still magnificent.