Dull seagull?

I couldn´t imagine that my reflection-shot from yesterday would make such a great illusion that even my brother, an experienced ornithologist, would ask me if I had to wait long to take the shot.
Magicians never reveal their tricks to anyone, and I´ve been thinking about whether or not I should say that the seagull was in fact just a dull(?) sticker on a shop-window.
And now you know my decision!