The images in the FlexiLayout project are not imported into Vantage Advanced Designer. Is it correct behavior?
This is a known limitation. It is not possible to import images as in the FlexiLayout project they are stored as separate pages, while Vantage works with documents. As Advanced Designer does not provide tools to assemble pages into documents, the documents should be uploaded manually using Upload button in the Extraction Rules Activity:
...or in Documents menu: