Letters, briefs and reports can be shown with their own typography. Automatic keeps that only while none of your settings above ask otherwise.
Narrows the reading column so each line is shorter and your eyes travel less from one line to the next. Phones keep a full-width column.
Keep Full Width leaves tables, charts, code, videos and galleries at their full size, so nothing is squeezed out of shape.
Category
What AI vendors say in their marketing, checked against what their contracts, terms and products actually do.