Nature's Gradient

Recently we were at FOWA (Future of Web Apps), we were walking to hear a speaker when something caught my eye. It took me a second to realize it was the setting sun was making the lettering look like they faded out at the bottom. I took out my iphone and snapped a quick pic. This effect is a simple thing, but I've never noticed anything like it. Maybe the architect or designer did it on purpose or maybe it's an awesome accident. Either way, I thought I would share it.