I've seen many, many examples of scientific presentations from the National Laboratories in which virtually every slide is oversaturated with information. If this were an isolated event, I wouldn't have given it any thought. But I've noticed this pattern in presentations over many years from among presenters hailing from US national laboratories. Though my field is computational science, I've seen talks from national laboratory scientists in other fields and their presentations also have this same characteristic.
In academia, I've been taught to keep slides as simple as possible, with as little info per slide as necessary. My understanding is a presentation should be though of as an "advertisement" for the paper to be published. Thus, presentation slides should be designed to preserve the audience's interest. One method of keeping the audience interest is to not overwhelm them with too much information all at once (e.g., not too much text and not too many pictures in a single slide). I presume this is universally true, regardless of discipline.
However, the overwhelming majority of national laboratory presentations that I've seen seem to fill up virtually every available space with as much information as possible. Why do presentations from national laboratories tend to contain so much information per slide? How does this meet the needs of their target audience?