He's doing his best to keep from saying anything overtly negative! He does not want to manifest bad luck on accident!

Laying out a plan for what they can do is very helpful, and Shinji nods along as she lays out what still needs to be done. "Mm, maybe we should leave the actual fish shopping for last, unless one of us wants to go right back to the hotel to feed Pen Pen right away." Or they could go around hauling fresh fish around while trying to get information, but that sounds probably more cumbersome.