The Omega's antireflective coating is very weak when compared to the Grand Seiko's. Just before the 6 o'clock index of the Grand Seiko you will find a faint blue circle. That same reflection looks like a lamp on the Aqua Terra located just before the 7 o'clock index. There is a second picture below where I switched the positions of the watches while not changing the camera position at all.
The Omega is now on the left, so you can find the lamp just before the 6 o'clock index as a bright spot. The Grand Seiko's reflection is now just before the 7 hour index, a barely noticeable bluish ring. This comparison shows that anti-reflective coating is not the same (within different models of a brand) or between brands. I suspect that the Grand Seiko has inner and outer anti-reflective coating on the Sapphire crystal while the Omega's Sapphire has a much weaker inner anti-reflective coating only.