Trunks could have tried mimicking a cat's silent footsteps and Piccolo would have heard his approach. Whether he would have responded or not was another story entirely. The green-skinned shinki took his time gazing around before finally acknowledging the other's question. He glanced over almost as an after-thought.

"As well as can be expected." In other words, he was fine but he also considered the point moot as nothing would change the way things were here. He could spare to be a bit happier but those were the circumstances. Also known as: I don't do small talk so please forgo the formalities. Which the silence that followed probably hinted at as well, considering he didn't have the courtesy to ask anything in return.