I'll introduce one of my favorite chapter arts and why I like it so much
Just a reminder this is my personal interpretation!!
Firstly, let's analyze the cards we have visible on Scanor's hand from left to right:
Meliodas on his demon form is a Joker card
Ban is a Jack
King is a king (for obvious reasons lol)
And Scanor himself is another king card.
The joker card for Meliodas could be representative of his power. — since the joker can be used to replace any card— Or maybe to how the Sins saw this form of him; someone who isn't what it seems.
A Jack card for Ban is probably linked to his loyalty to the Sins or to Meliodas and Elaine, since the Jack itself is a figure indeed usually linked to loyalty.
King is a king, because he is the fairy king. (Sherlock Holmes is jealous btw)
Scanor being a King as well could be a small reference of how he was born into royalty!
Now going over the game itself:
I'm not an expert on card games, I really am not. I don't even know what they're playing, but let's just go by good ol' assumptions just for fun.
It's likely that Scanor is trying to form a Royal Flush using the joker to replace the Queen or the Ace. But given he has two kings on his hand, he'll have to get rid of one of them to be able to form a proper Royal Flush.
This is likely a foreshadowing to his death later on!
In the game shown in the art, he'll likely get rid of himself to form the sequence he wants and win.
When he dies, he dies sacrificing himself so that the Sins could win the battle against the Demon King. (sorry if it's wrong, I don't properly remember the details)
