On the left, the cover to STRANGE ADVENTURES #75, by Gil Kane and Bernard Sachs, circa 1956.
On the right, the cover to BEYOND THE UNKNOWN #23, by Nick Cardy, circa 1973.
What happened in between? Jack Kirby and the Marvel explosion, of course.
As Stan Lee and John Buscema explain in How to Draw Comics the Marvel Way, while there is certainly nothing wrong with the original drawing, the revised one is more dramatic, with the ape's legs further apart, the librarian showing more terror in her pose and her expression, and actual people reacting in the background. (Plus, they got rid of the valise.) In short, the cover on the right is how Marvel would have done it.
It's a little funny to me that this kind of encapsulates the impact of the Marvel way almost better than any other example. It works as that kind of example specifically because it's a before-and-after recreation, but also, it has apes.
For the record, I kinda wanna hug the ape on the left.