alt Hacker NewsYou can get a good idea by reading Retraction Watch and following a few papers/scientists who show up in it. That defines the current norms.
To me, a single significant error of any kind brings the entire paper into question. If a less important figure contains an image duplication, that makes me wonder if I can trust any of the images.
That's the administrative aspect of the question. But as a scientist, I'm more interested in knowing if the result is real. Sometimes even fatally flawed papers make valuable contributions, because the proposed approach will lead to the claimed result, once done properly.