Modifying this control will update this page automatically

Hear VoiceOver summarise a web page on Mac
Hear how many headings, links, tables, landmarks, live regions and more are on a web page.
Note: VO represents the VoiceOver modifier.
Press VO-Shift-I.
VoiceOver speaks statistics only for the types of items listed in the Rotor when viewing web pages.
To set an option to have the summary automatically read when a web page opens, open VoiceOver Utility (press VO-F8 when VoiceOver is on), click the Web category, then click Page Loading.