A working demo web site
Sorry, I am unable to understand you.
This is a fully working demo website – none of the examples there are screenshots. Feel free to run it on a desktop to check the layouts rearranging. Which part of it is not working or not a demo? Let me know and I will make sure it gets fixed.
(+ graphic interface to avoid typing code…)
There is a full graphical interface for the plugin, which is launched when you click on the “Add / Edit Photonic Gallery” button in the Classic Editor, and if you click on the Photonic block while using Gutenberg. See here for screenshots of what you should see. This interface contextually builds out the full gallery for you, including giving you a listing of all your albums, layouts etc. Are you unable to see the buttons / Gutenberg blocks?
Also note that you can use this page as the starting point for all your documentation, as well as the Photonic → Getting Started page in your dashboard.