When you upload a PDF, we do not do any processing on it.  We simply sell your PDF.

The same is true with EPUB and MOBI uploads via our "Upload" writing mode. Our Upload workflow is exactly that: you make the book, we sell it.

When you use our book generation workflow, then we output an ebook in PDF, EPUB and MOBI, like the many you see in our store here:
https://leanpub.com/bookstore

If you want a representative example of what one of these books looks like, you can download R Programming for Data Science for free from
https://leanpub.com/rprogramming

(You can also buy it for money, of course -- it's a great book!)