these are notes only.
The slideshow uses PAGES now (not Posts) – this is set in Appearances > Flexible Theme > Slider
The images are fed from the Featured Images set for the 2013-2014 pages and the 2010-2012 page (you can add more from the Appearances controls)
To change the image, open the relevant Gallery page and change the “Set Featured Image” (bottom right) – be sure to upload an image that is 960 wide x 360 tall
This Featured Image is NOT used in the Gallery’s Juicebox Slideshow (all the Juicebox slideshows are set to NOT use the Featured Image).
The order of images seems to be based on Creation Date, not the post name! The creation date can be manipulated in by clicking Quick Edit or Edit.