They may include minor scratches, small edge whitening, or foil imperfections such as print lines, foil seams, or slight foil peelin
Let me know in the comments below, and come share your finds on the Draftsim Discord
You can duel Pegasus, Kaiba, Yami Yugi, Dark Joey, and Yami Bakura there
If I were looking for a PSA 9 copy of a card I would not buy a copy with that much scratching or whitening (slightly miscut corners dont bother me nearly as much though)
Planes usually have two important parts: A main ability which can be a continuous effect, such as Tazeem in Zendikar (whose ability is that creatures can't block while this plane is active), or a triggered ability, such as Undercity Reaches from Ravnica (which allows the controller to draw a card each time one of their creatures deals combat damage to a player)
The case enhances, not hides, the intricate details, allowing you to admire your collection in all its glory