Updates for poster art.
iTunes now supports layered images (LSR) through Transporter delivery. The layered image format is a zipped folder with the extension .lsr containing a set of folders, json descriptions, and PNG .png files, one file for each layer. The layered image must have a minimum of 2 layers with a maximum of 5 layers. The folder contains the PNG images along with a manifest describing the order and position of each layer. The LSR .lsr file must have a minimum resolution of 2000 x 3000 pixels.
You can also now update existing poster art through Transporter after a title has gone live on the store. Both flat (.jpg, .png) and LSR files can be updated, but these updates are subject to review by Apple, and may not take effect immediately. To learn more about poster art, see the iTunes Package Film Specification.