I can remember twice being in a hospital (in ER) with my wife, concerned with something or other going on with her heart issues, and could hear people at the desk laughing and joking, one time even as we buzzed for help. Pi**ed me off something awful. But after I cooled down I figured they had a tough job, and probably had to not get emotionally involved or constantly be running around anxious about the patients, otherwise they'd burn out quick. Though you'd know better than me. Let me know if I'm wrong, in which case I'm going to go wring some necks.
As to your question, fwiw I wouldn't consider it unprofessional, unless it was maybe dressing like monsters in a pediatric wing or something... if anything I rather like the idea... makes you people somewhat human, as opposed to the usual clinical and inhuman distance or indifference, bordering on rudeness, I usually encounter.