"Alice! You can attack with light too!?" Walker was hit pretty hard with the realization that he had never actually asked or learned about Alices' capabilities. He had only ever known her to heal using her skills and not condense light to a point that she was able to create something physical. Overall, this was a pretty big shock and lesson to him for not being able to pay attention well enough.
The smile on Alices' face showed that she was happy that she had surprised Walker, however, she was not going to let it cause her to lose her own focus. Her eyes were locked on Su, "No armor." She knew that Su wanted light elemental resistance and that her armor would cause her not to gain it as well as she wanted.