Maybe it depends on what you wear and how you behave otherwise. If you're slacking on the computer, wearing a torn T-shirt and shorts (better yet, PJs), and you have the TV going and the dishes still aren't done, and you haven't picked up the empty drink cans from yesterday, and you just happen to drop by a hub and fiddle with it, that probably doesn't violate the core values. After all, you're using hubs as a way to slack off the other stuff. Good job! (Or however slackers would term it).
If I am still in my PJs (trust me on that one), coughing like crazy, messing with the computer and avoiding anything more strenuous than filling my water glass, and maybe I somehow JUST HAPPEN to write a line or two, that's probably still slacking, right?