This module was written to allow you to customize your Odoo instance’s shortcut icon (aka favicon). This is useful for branding purposes, but also for integrators who have many different Odoo instances running and need to see at a glance which browser tab does what.
More info about favicon: https://en.wikipedia.org/wiki/Favicon
Upload your favicon (16×16, 32×32, 64×64 or “as big as possible”) on the company form. The file format would be ico, gif or png with 16×16, 32×32 or 64×64 pixels and 16 colors. Highers resolutions or colors support depends on the used browser, but most modern browsers do.
Note that most browsers cache favicons basically forever, so if you want your icon to show up, you’ll most probably have to delete you browser cache. Some browsers can refresh the favicon, accessing the URL <base_url>/web_favicon/favicon.
You have a sample SVG that can be used as template for generating your icon in /static/src/img/master_original_favicon.svg. You can also search for some favicon generators across the web.