Image display on non-IE capable browsers
Option to convert Visio diagram to SVG image when displaying on browsers not capable of running the Internet Explorer (IE) Visio viewer control. This includes mobile devices using the Confluence mobile support.
This requires Image Conversion Support. An add-on configuration option allows the Confluence administrator to set the default behavior so all existing macros can take advantage of the support immediately.
SVG support is available in most modern browsers according to Wikipedia:
All major modern web browsers—including Mozilla Firefox, Internet Explorer 9 and 10, Google Chrome, Opera, and Safari—have at least some degree of support for SVG and can render the markup directly.