Your pic wont open for me Heavyarm.
Funny thing - my BG used to come out in daytime whenever I fed the tank. Then when he was about 8" I added four 3" Oscars. From that day onwards he never came out again in the light until the Oscars were removed again.
They never bothered it, and at 3" they couldnt really, but he obviously recognised them for what they were. He's fine with other big fish - he just doesnt trust Oscars !!