Another image illustrating that you can make a glass of lemon juice even when you can't avoid shooting a glass-framed picture with a flash :)
First one is http://www.furaffinity.net/view/2609868

For those who can't read between the lines -- it isn't my drawing. It is my photo of a drawing made for my wife's business a few years ago, being creative with positioning the flash reflection, posted to show one fur what a good positioning can do :)