It’s taken me hours to get up to this point so allot of sweat and tears went into this. 
First I had acetoned this JP card and then a Wotc star foil as well wich I have shared in a different thread before.
When I realized the JP pattern is mirrored I acetoned my third and last card (EU base set cosmos) but it seems I was to rough on it and it didn’t turn out good. Ofcourse just mirroring the JP picture with desktop is easy but having the card physically with you has it’s advantages.
Indeed, I also use that plus looking star to see the direction of the foil and somethimes other things as well because it’s not always visible. Then I went through all the sets in JP, ENG and foreign and written down the directions of cards I could find. Still working on it actually because I get sidetracked often. 
I noticed a few things but it’s kind of a mess because some sets go in all directions.
Edit: I think the cosmos foil has four layers to it and every layer can be seen reflecting from a certain angle.
When looking at it normally you can see two layers at a time but when looking at it from the top at a difficult angle you can see three layers but I believe it’s not possible to view four reflecting layers at once.
Just wanted to add this little bit of information. (I could be wrong tho, not saying that I figured it all out or something ^^)