How to get the color burst wallpaper frames
The pictures in that advertisement do not come preinstalled on the MacBook Pro with (or without) the Touch Bar and do not seem to be provided by Apple separately. It appears that those images were used solely for advertising purposes and are not available. There are three similar "color burst" images with combined colors (See pictures). 

Note: The photo quality have been degraded by 70% to allow for them to be uploaded.







If you would like to get the Photos you can make a feature request at https://www.apple.com/feedback/.