If you drop in on a photography critique you might hear a mantra repeated over and over, a directive to simplify a composition. Photography is the art of exclusion, or leaving out of the frame things that are not important to tell that story.
It is the reason that advertising images are careful orchestrated and artfully retouched to remove any distracting objects that dilute that campaign's message. And also the reason that a lot of catalog photography is done on completely white or simplified backgrounds.
But rules are not universal and there are reasons to add things to a composition. Context is very powerful, and when photographing events like conferences, lectures, banquets, etc I try to give my images depth by showing the subject in the context of the event.
Conferences are often held in larger rooms so audience members can have empty seats around them and more comfortably set up their computers, notebooks, coffee cups, etc. The two images above were shot within a minute of each other -- I shot the image on the right first and then worked to find a better angle.
The more useful image to my client shows that the event had a healthy turnout and because of that the discussions were more vibrant.
Photographs of the speaker also have more depth when we see at least a hint of the audience. It no longer is a solitary person standing at a podium, they are now in a room filled with an attentive audience.
These sort of events will often include breakout sessions, or a break for lunch or coffee. This is another chance to show people interacting.