The correct pixel format for ‘Brand Kit’ images and file is a 1x1 ratio, with 3000x3000px maximum.
The correct pixel format for ‘Wallet Pass’ images and logo files is a 1x1 ratio for the corner icon, and 1032x400px for the larger photo.
These can be adjusted by navigating to settings -> 'Apps' and and scroll down to ‘Wallet Pass’. Press ‘Edit Design’. Once on the editing page, locate the ‘Styling’ button in the top right corner to upload your logos + images.
The correct pixel format for ‘Rewards’ images is also a 1x1 ratio, with 3000x3000px maximum.
Please note: for the Narrowcasting (on the Business App) the image size is dependent on the screen size of your tablet device.