The message means that Cydia no longer thinks you have an iPad, despite it being an iPad. As Marilyn correctly pointed out, this may well be due to installing another tweak or app which has messed with your settings. For example, hacking an iPhone app / tweak onto the device in a non-standard way.
I don't own this theme, but it also doesn't look right that there are two wallpaper packages with the same name being installed. Are these dependencies (and legitimate ones) ?
I couldn't identify them in Cydia on their own when I had a look just now.