Google is now testing an intelligent shortcut in Chrome for a selected number of users depending on their usage pattern.
The new context-based button is rolling out slowly to users who use the stable release of the Chrome App on Android (version 101). The intelligent shortcut will depend on how you use your browser, so the user may see a new tab button, share option, or a voice search button. If you want to change it or remove it, long-press the icon, click Edit Shortcut, and you’ll see the Toolbar shortcut selection.
If the said feature doesn’t appear yet on your Chrome browser, you may try it yourself by tweaking the ‘chrome://flags/#adaptive-button-in-top-toolbar-customization’ flag.
Previously, this new toolbar button had already popped out for Chrome 92 Beta users, which means it has been existing for about a year now. Take note that despite rolling out in the latest stable version of Chrome, it is still in the experimental phase so watch out for more updates.