Fast forward to today and we see these principles everywhere: iconography, logos, typesetting.
The Google “G” logo, for instance, isn’t geometrically perfect. Its designers adjusted it away from a perfect circle to appear balanced. If you contort the logo to undo these adjustments, it just looks weird.
As does the play button when mathematically centered, or a leading-aligned paragraph when you align the glyphs by their actual shape.
Apple has a long history of prioritizing visual perception over mathematical precision in their interfaces.
Even as far back as the 90s, Apple’s font rendering methodology has been “make this text look as similar as possible to a printed page at the cost of some blurriness.”
Meanwhile, Microsoft’s has been “cram the glyph into the nearest pixel at the cost of staying true to the font’s design,” which caused type to look thinner than it actually would appear when printed.