when i use the art creator to create an album grid of the last year i get a nice 5x5 grid with images Top 25 Releases last year for sanojjonas
but if i then download the image i get one album that is just all white.
as you can see when you click the link you will se that all the albums have an album cover image.
this is what i see when i click on the url
Sometimes Refresh (Ctrl+R) helps. 
oke so i tried downloading the image multiple times and now it is what i expect
You can now have this graphic made on a t-shirt. 
This seems like the CAA had a timeout. It happens sometimes.
Once I had only one cover art loaded
it just felt weird that all the images where there in the example and then on the export a cover was missing.
i guess the example loads the images in my browser one by one. and then for the export somthing on the server loads all the images and then generate a new images.
so in that case it is possible that it would load it locally out of cache and on the server it had to download them?