Previously in How to present MS-DOS screenshots, I encouraged readers to take the original pixel aspect ratio into account when showing pictures of old games. There’s also a subtler issue to consider: the blur analog display systems had.
In the context of modern pixel art games, video game historian and preservationist Frank Cifaldi proposes in a 2023 tweet (screenshot) that one should do vertical and horizontal scaling separately and differently:
Whole integer nearest neighbor scaling on the vertical axis, bilinear scaling on horizontal. The slight blur is consistent with what a CRT does and is not perceptible unless you glue your face to the screen.
It’s a subtle difference. In the horizontally blurred case (center), the dithering on the rocks is less pronounced and Jazz’s facial expression is now easier to read. The pixel art crispiness is still there, unlike in the blurry bilinear case.
In the original tweet, Cifaldi’s reasoning was that the slight blur is “consistent with what a CRT does.” My understanding is that this is definitely true for most TVs, especially when connected to game consoles via composite video. So if you want your game to look like a 90’s console game, his advice seems solid. Source is this excellent 2023 blog post.