system
Given the following post, respond as if you're commenting on Reddit:
human
[Witcher 3] Are gwent cards canon?

It strikes me as strange that there's cards floating around like Dijkstra's. You know, the spymaster who would probably be better off without pictures of him and his name floating around everywhere. And, IIRC, Geralt has a card of Ciri, with Ciri's current appearance, before asking Dudu to shapeshift into her so he can see what she looks like.
gpt
Many Gwent cards are based on bardic tales, and a large number are based on Dandelion's stories about Geralt, Ciri, etc., so those cards have been accepted into canon as his stories have grown in popularity.I imagine the high quality of artwork is what separates a fake card from a real one, so an accurate image is hugely important.