Dry hopping is, in general, a pleasurable experience and one of the nicer jobs in the brewery. For one, you get to smell lots of lovely hop pellets, and even sneak the odd one to rub between your fingers to release the oils and get to the true soul of the hop, and for another it's not (generally) a dirty or strenuous job unless the CT decides to spray you with yeast and/or beer.
This dousing is a very rare occurrence but sometimes, generally if the hop pellets are powdery or loose, the many bits entering the beer will create "nucleation points" which draw the CO2 out of the beer and creates a sudden, sometimes violent, gushing of froth which can catch you unawares if you're gazing reverently into the tank and not watching out for it.... not that I ever do that you understand.
But what are "nucleation points"? Well, you could always do the usual thing and Google it, but the best example is to imagine a dirty glass into which you pour beer (or any carbonated drink)... the sides of the glass suddenly become covered with bubbles which the dirt is bringing out of suspension. The other commonly seen manifestation are the new-fangled lager glasses which create a stream of bubbles from the bottom of the glass; this serves no purpose except to look pretty and make the beer go flat extra-quickly, but it's caused by a dimpled bottom (fnarr) which, as you've probably guessed, brings the CO2 out of solution and creates the stream of bubbles.