Images
SC 1.1.1 - What does "Non-text Content" mean?
Every image on your site is invisible to somebody. Not because their screen is broken, but because they browse with a screen reader, or because the image failed to load on a train, or because they turned images off to save data. What reaches them is whatever you typed into the alt attribute. That is the whole point of the first success criterion in WCAG: anything that is not text needs a text alternative that does the same job.
