links to root level of OS guidelines means nothing
again, breaking what EXACT UI guidelines makes Photoshop's learning curve steep?
I mean, it's OK to have big mouth as long as you can prove your points, you have troubles with second part so far.
You are angry and gave an emotional, not rational response.
Our topic is about thumbnails. I provided a link about (classical) design law. You did NOT provide anything to sustain your point. So, the one which has „big mouth” (to quote you) is you - not me.

Waiting for scientific links proving that Lr's UX design is the best one.

Also waiting for links from OS design guidelines proving that Lr follows Windows/MacOSX design conventions.
You must provide your point because you are proposing something.
WRT Photoshop - it is enough to compare Photoshop UI with PowerPoint (also a graphics program).
Microsoft recommends tabbed/ribbon interface for the toolbars. Where is it in Photoshop?
There are glaring and striking differences. There are too many to mention them and here isn't the place (just mentioning Tools | Options which in Photoshop is Edit | Preferences). If you would have just a little experience (or rationality?) then you would find these.
Ah, FINALLY.. next time, skip all your chatter and go straight to the topic to save everyone time.
This is a moot topic. Thumbs design here needs a complete overhaul - from a drop-down approach to an on-screen presentation. Not worth it IMHO because it hinders the UX for our actual user base and it doesn't provide any advantage to anyone. It will draw away the actual users while it will not attract new users. XnView MP is aready much better than Lr in the areas in which XnView MP is strong. It cannot compete with Lr in the areas where XnView MP doesn't have a proper engine (ie. Raw editing).
ps. you remind me one annoying user who liked useless arguing, but was not able to prove any of his points.
What a coincidence that you became active once he has been banned...
Do not trust your thoughts. They are wrong.
PS: Waiting for you to provide
your points!

Don't forget the links to the exact guidelines!