If you click on an earlier (random) 'speech' from 2016, you'll see that the size of the auditoriums has steadily grown. The attendance is also higher.
After listening to it (in the background) you'll find that it doesn't have much substance. It's mostly fluff, a lot of crude jokes about Spacey and DNC members, appeals to American exceptionalism (invariably followed by the predictable USA, USA, USA), examples of the pettiness of the progressive left (there are many) and of course why 'his side is going to win.'
His oratory skills aren't particularly great and his mannerisms are self-indulgent and self-congratulatory. His main strength is appealing to the right target audience (twenty something college-age idiots).
Funnier of course is that he's more than capable dealing with the talking head media figures/interviewers of the MSM, illustrating just how incompetent these media figures are. He's similar in that regard to 'I keep a list of abstruse words on my smartphone' Russell Brand.
Forum-autist, coming through!