FYI it's a reference to something else. He's basically calling you a fed/gov shill. It's a reference to glow in the dark CIA agents that schizophrenic late programmer Terry Davis claimed were following him. So it turned into a meme, and now glowie means fed/3 letter agency/police and saying that something glows means it's shady. I dont know how he got that from your comment.
(A comment that "glows" would usually be something like: hey fellow members of radical political ideology, who is up for letting those politicians know what lead tastes like? Let's conspire to commit domestic terrorism!" )