This matches the text directly with the pixels.
The uniform width allows for a pixel grid of a complete text paragraph. This kind of visual art is not just made with any font, but with monospaced fonts.
And not any possible letter, but just one of the 128 letters which are part of a character set called ASCII. For the younger generation not known with ASCII art (logically, that’s a pre-internet thing): ASCII art is an image displayed using letters. Originally started as an underground movement, but not much later a major hit. When the character encoding standard “American Standard Code for Information Interchange” was introduced in 1963, hardly anybody could foresee that a little more than a decade later the world would loose itself in an early digital hype: ASCII art. Case study: From ASCII Art to Subpixel ASCII+ Art