For the benefit of R2 and future applicants, I'd like to say that my slides had no pictures or charts at all; they involved text only, and I got in.
I understand I might be in the minority that got in with no pictures, but I also think I was in the minority of applicants with no pictures, regardless of admission or rejection.
So, in summary, I do not believe that we have any evidence that shows that they really wanna see mostly pictures, or even any picture. You may ask, why would they ask for a ppt, then? Well, perhaps:
a) To see if you freeze and end up doing something incredibly stupid
b) To see if you can get across some point you're trying to make without using too many words
c) To see if you can organize elegantly an idea into 4 sub-ideas
d) 'Cause they're bored
It could be any of those. Or maybe they do want mostly pictures and my admission was a fluke. Who knows.
My humble, personal advice is: if the point is to be creative and original, the consensus of gmatclub (or any other community) should not be your inspiration, because then you're not original anymore, right?