I think they see the polished stainless, and react to it much more than they see a bead blasted stainless barrel. I have rifles with both finishes and wrap the polished barrels but don't worry about the blasted one.
I bought a new rifle last winter with a polished stainless barrel and took it out on a clear morning. I set up before sunrise not thinking about the rising sun being a problem. As the sun rose, I ended up sitting in the sunshine. A coyote walked into the field along a creek about 200 yards from me, and as soon as I moved that rifle, that coyote turned and trotted back into the brush. I'm 100% positive that that coyote saw the sun reflect off that rifle.
I also have a hunting buddy that bought a fluted stainless model 700. As soon as he stated using that rifle we noticed we weren't getting as many call ins. He painted the barrel and things picked right back up.