For a Sprite Kit Game i am providing my LaunchImages through an AssetCatalog.
The catalog looks like this:

The image is shown correctly on:
- all iPads
 - iPhone 6
 - iPhone 6 Plus
 
The image is not shown on:
- iPhone 4S
 - iPhone 5
 - iPhone 5S
 
I am developing for a minimum target iOS 8 
Can you figure out what is going wrong? As you can see i even added the portraits for the iPhone to see if anything is loaded as launchimage - but nada..
