I've been always fighting with it to no avail.
I recently received my repaired Mi4c with 6.12.22 (the repaired couldn't go beyond). Then I upgrade it to the first Android 7 version, and then to the latest MIUI 9 weekly release. So, the cleanest installation I could have. I do have the folder <internal storage>/Android/data/com.mfashiongallery.emag/files/Pictures/defaultImage/ with the two (I guess sample) files 1 and 2, with no extension. Dropping files in that folder does nothing. The wallpaper carousel is showing random pictures even if I disable all categories in the configuration. What I'm being so dumb to miss? Is there anyone that got it working?
Cheers to everyone!