It's a film term that has acquired a secondary meaning in porn. In regular movies it's a shot where you blow something or stage some similarly expensive setpiece that will provide a visual highlight for the film, and it's still current in that context - on a crew it's normal to discuss scheduling in relation to the day's 'money' shot, and the term is often stretched to include whichever shot is the most aesthetically important one for the current scene. Obviously, in this case the person explicitly referenced the porn context.

I thought that the porn context was quite inappropriate myself and broadly supported Richards at the time, although I also think she should have taken her concerns directly to the organizers first. I'm not really offended by porn, but I'd rather not watch it myself, and it's very predictable that it will be offensive to quite a few other people, who'll feel excluded from that presentation even if they're interested in the technical topic (making effective screencasts). In the organizers' position I'd have asked the presenter to consider something more general, such as 'what you can learn from movie directors'.