My tablet is a Google Nexus 10 and it has an XHDPI screen with a size (I believe) of Extra-Large.
I've put the assets for it into my drawable-xhdpi folder.
I then decided to test creating another folder, namely drawable-xlarge-xhdpi and stick some assets into it. I left the other resources in drawable-xhdpi.
I ran the app and it ignored the resources in drawable-xhdpi and picked up the resources from drawable-xlarge-xhdpi.
I then renamed drawable-xlarge-xhdpi to drawable-large-xhdpi.
I ran the app and it ignored the resources in drawable-xhdpi and picked up the resources from drawable-large-xhdpi.
I then renamed drawable-large-xhdpi to drawable-normal-xhdpi.
I ran the app and it ignored the resources in drawable-xhdpi and picked up the resources from drawable-normal-xhdpi.
I then renamed drawable-normal-xhdpi to drawable-small-xhdpi..
I ran the app and this time, it ignored the resources in drawable-small-xhdpi and picked up the resources from drawable-xhdpi.
So it seems that the Android System appears to see the Nexus 10 as having a 'normal', 'large' and 'extra large' screen.
I have no idea what's going on here, but I'm sure there's someone out there who has some handle on this and who could
Edit
It just gets weirder, even if I put some resources into a folder called drawable-normal-ldpi (Could not be farther from my actual device which is XLarge (Screen) and XHDPI (density)), it still takes resources from that folder and ignores the ones in the XHDPI folder.
I read through, and thought I'd understood the Official docs on this subject but my latest test shows that I'm clearly not.