I had originally shot this bottle (that had been left on the seawall by some inconsiderate jackass the previous night) from behind. (Yes, the fact that it was left there by some jerk with no concern for his local environment didn't preclude me from using it as a subject.)
But then I went into the beach to do some other shots and saw the label from the front. Sol. As in, "Sun". Being lit by the warm, morning sun. (Well, warmish; it had lost the best of its warm tones about 5 minutes earlier.)
Still, sunlight on glass usually works.