I have heard of both types of presentations being done, but it depended most on the subject and what assessment the staff have set.
As mentioned above, you have other smaller classes in which you’d typically present, so most of the time you’d be presenting in a lab or classroom-like setting like you did in high school to an audience of 10 - 25. However, in my Japanese classes (which is under Arts) at Monash, I did have some marked orals with just the lecturers and in higher levels, small group presentations with just 5 - 10 people (including lecturers) in Japanese. (Languages are unusual though, and usually it’d be to around 10 - 30 people as well.)
On super rare occasions when the entire cohort has been small (50 or less students), I have heard of short oral presentations done at a lectern almost as if it were a student taking a lecture, but these are very rare and even in this case, it’s unlikely the entire cohort would be forced to watch each and every one of the presentations in an undergrad degree (with only Honours being the exception).
Edit: I stand corrected on my last paragraph.