Honestly - I am a bit "empty" and ask myself if I did mix something up or if it is right this way.
When I am on this page
https://my_spc/com/custom_station/ullmann_magistrale_9005/P8060150_k_1.jpg
And enlarge the picture, then I have this address for the picture:
https://my_spc/com/zp-core/i.php?a=custom_station/ullmann_magistrale_9005&i=P8060150_k_1.jpg&s=1400&cw=0&ch=0&q=85&wmk=!&check=4316dc4f3331d7e59812efef3595081c0bed4609
When I now copy the address and short it to:
https://my_zpc/com/zp-core/i.php?a=custom_station/ullmann_magistrale_9005&i=P8060150_k_1.jpg
Then ZenPhoto is redirecting and displaying the hidden album directory in the addressbar:
https://my_zpc/com/alben/custom_station/ullmann_magistrale_9005/P8060150_k_1.jpg
So, is it a bug or a feature?