Shiro had not really followed the invitation, per see, but rather decided to stroll around town. He had been far too long within the hotel. After all, he had never really stopped and lived in a place. Lived, being the key word. He was a Death God, someone - something - that carried the souls of the deceased to the other side. He had been born that way, made for that sole purpose, and this whole "living" thing was exceptionally weird and new to him. He had still maintained part of his powers - he could see departing souls and he could disappear and appear at will, he could travel around and float, and probably could appear in people's dreams - he hadn't tried that one yet - but... he couldn't help anyone anymore.
His purpose was... gone.
So he had started to get acquaintance with people around the hotel. It was hard, his people's skills were null and he was a bit too naive to understand how things worked, but...
Well...
He was trying.
And when he noticed Demyx making all of those replicas out of water, he stared in awe. He had never seen anything like that - anything at all. He was floating a little far behind the sitar player, blinking and enjoying the show in complete silence.