Q - Hi Amir,
How do I differentiate between the shiny and non-shiny side of the screen?
J - Canada
A - Hello
From past experience it is hard to notice a difference but the good news is that both ways the film works very nice.
If you want to do it 100% right, then the outside side of the film(the side that should be facing the screen) is the side which is covered by a transparent thin film layer.
Try to take the 2 layers just a little bit apart in order to find the side which should be facing the screen.
One you find the outside side , make it face the screen.
I hope this info helps.
All the best