Someone took my picture

I was riding the 'L' at dusk today. A young couple sat in an aisle-facing bench, two or three rows in front of me. Out of the corner of my eye, I saw the female half of the couple take a point-and-shoot digital camera out of her bag and start taking pictures, the flash turned off. I wasn't sure what she saw that was so interesting, and I didn't really care. I kept most of my attention focused on the dimly lit streetscape passing by outside the window.

Suddenly, a red light appeared, reflected in the window at precisely the point where my gaze was fixed. The light was from the camera and was aimed at my reflection. I can imagine the picture: the ghostly image of some random passenger who happens to be me against a blurred silhouette of nondescript buildings, trees, and the bell tower of St. Ita's.