Custom wallpaper on Xubuntu 14.04

I am a big fan of XFCE.  So much so, it is my desktop of choice on most Linux desktops (servers, if they are mine).  I have two AcerOne laptops that have not the fastest hardware (one has 8GB memory but the poor AMD C70 dual core is not that fast) so I decided to update them to Xubuntu 14.04.  One of the things I like to do is customize the wallpaper.  I gave up on the AcerOne with the AMD C70 but the other one I finally made it a priority to figure out why I could not select my own wallpapper.

Here is what the desktop settings I get when I navigate to my wallpaper directory (~/Pictures/wallpaper):


Notice that all the jpeg files are greyed out and I cannot select one.

This post in the UbuntuForums had the solution but I did not understand the wording of the following solution at first:

It works here. Yes in Desktop settings the individual pictures are greyed out , but if you click "Open" all the pictures in the parent folder will be displayed in the desktop settings app's window, then just choose the wallpaper you want by clicking. So, you have to choose a folder instead of a picture in the dialogue, then choose the picture only after you have picked a folder.
Note the folder in the screenshot is "Pictures" rather than "Backdrops". I only have one picture so only one is displayed. I guess you should put all the wallpapers in one folder then.
Well I guess that is not very intuitive.

The solution of course is navigate to the directory ABOVE the directory that contains the image files and select the directory.

Instead of double-clicking press the Open button.  This will populate the thumbnails with the files.

This appears to be a usability feature that did not quite understand.  Too bad the developers do not support selecting individual files.   I have been using XFCE for quite some time and recall this working before.  Oh well, lesson learned.