I'd like to see it too, I couldn't find a picture of one.
Asked our SMPS expert at work ages ago what was actually making the sound from one and it's usually the ferrite core of the transformer changing shape rather then the windings, which I first thought. Sometimes caused by the converter working at a lower than designed frequency. Just a bit PSU trivia .
Interesting - so that points to the transformer itself rather than the rather obvious assumptio n I made that it must be the domed cap... yes, what you say makes sense, vibration which is perceived as buzzing...