Or you could use “Import My Saved Data”, there is a little difference from “Import Demo Data”, you could use this button to import the real demo images(not placeholder images):
Click “choose file”,
Pick up the xml file, you could find the xml in /functions/theme/ folder(download demo data here: Theone, Bee, Aside, Center, Real, Upfront, Blogary, Mellow, Za)
Click “Upload file and import”
The page will be shown, set author and attachment, click submit:
Note: you may have to repeat the Import step until all demo content import.