Take DPI Into Account

When S compiles to a PDF, it ignores an image’s dots per inch setting, and considers only the size of the image in pixels.

So, for example, if you’ve specified that your 1200 pixel wide image has a resolution of 600 pixels per inch, you’d expect it to be two inches wide. Scrivener, however will only look at pixel width, and in many cases, print an image over several pages, and on top of text.