You’ve seen it. You might even be required to do it in your organization. It returns the word BRAND to its roots by tagging the flank of every slide with a hot and painful sting. There it is, the logo stamped somewhere on eeeeevvvvvveeerrrrryyyyyy slide:
This is connected with idealized post-Neurath design like Cook and Shanowksy's Department of Transportation signage from 1974, the most enduring pieces of which are the restroom man and woman:
Visual stories like people try with Prezi or with infographics. You follow a long story-like process that reminds me of a comic book, like in this:
You also have someone like David Carson, who challenges the audience to figure out the mystery of what is being advertised behind a messy scrawl of surfer-style graphics.
When you design a slide you have to decide where you are positioning your audience. Probably you will push them, at times, toward one side of the seesaw, and then draw them back so that you can keep them shifting and so that you can pull in everyone.
From the complexity perspective, you might imagine it is okay to have multiple foci on a slide. We can handle it. We will split our attention. But then, doesn’t the same logo on every slide then just begin to disappear? It becomes screen real estate we ignore because it stops interesting us. So then we are training our audience to stop paying attention to pieces of our slides, which is bad, and to the organization’s identity, which defeats the purpose of putting it on there in the first place.