ok, meanwhile I found the reason

Touch firmware 1.03 doesn't need new pictures, so there is no picture folder in the ProfiLuxControl-folder for 1.03

but if you did now an update from 1.01 to 1.03 you are lost here

-> search the application folder of ProfiLuxControl
there is a folder

C:\Program Files (x86)\ProfiLuxControl_V5125\ProfiLuxTouchFiles

(or similar)

in this folder is another folder "Pics102" - make a copy of this folder and rename it to "Pics103"

-> now you should be able update the pics