Annan had his lofty fake body raise the shield, but that was just a trap set for the Grey Professor.
Indeed, his lofty fake body could shoot a stream of light from that "hole."
The circular notch on the Goddess's Shield actually refers to a "ring" or rather a "lens." The power of light released through the ring could be constrained, diffused, or even bent...
It could roughly be understood as opening an acceleration gate and then connecting it to a Q ability.
Annan's previous Brilliant Sword had somehow already broken through his Wall of Ash; now, Annan was preparing to use an even more powerful skill, and the Grey Professor had to react accordingly.
Dodging the light was impossible.
He could only take it head-on.
Because the Grey Professor had yet to figure out how Annan broke through his Wall of Ash.
It wasn't some "halved reflection" capability.