Of course if a program says, "If you need to check your email during a break then feel free to use these computers" then it's fine to do so. And I realize that there are occasionally times when it would not be impolite to use your phone during the interview day. But the fact is that some applicants have difficulty with social subtleties, and those are the people that this advice is directed towards - if you are among that group then your best bet is to just keep your phone on silent and in your pocket.
Personally, I have a somewhat odd sense of humor. Early on in my interviews I did not try to temper it, because I thought that programs should "like me for who I am". It became clear to me that I was hurting myself with some of my comments (one PD asked me "Are you trying to tell me you have a problem with authority?"). After that I started to play it safe and I avoided such awkward experiences thereafter. I ended up matching at my #1 spot.
I understand the desire to think that a program should "like you for who you are", but the truth is that it's very hard, probably impossible, to get a very good sense of that during an interview day. We are both (programs and applicants) forced to make a decision on less than complete information. As such, small things can get amplified. So it is in the applicant's best interest to try extra hard to put his or her best foot forward.
And you know what? The same holds for the programs. I may have a gripe about some particular Cardiologist on staff, but I'm not going to sit around talking about that on interview day. I may like to listen to experimental German music while I'm in my office, but I don't do that when I'm interviewing. And our residents certainly don't eat a catered lunch every day of the week (only on Tuesdays
). Does this mean I'm being dishonest by trying to make a good impression during interviews? I don't think so.