Icons See documentation
Very simple: specify the icon's name that you'll find here, by ommitting the icon- prefix.
Note that Font Awesome icons are well supported.
Generates a bootstrap icon markup:
Html::icon('user')
You can set html attributes as second parameter:
Html::icon('download', array('id' => 'now'))
Images See documentation
Simple support for polaroid, rounded and circle image styling.
Second parameter can be a string, or an array if you need to provide other html attributes:
Html::image('...', array('type' => 'polaroid'))
Html::image('...', array('type' => 'rounded'))
Html::image('...', array('type' => 'circle', 'alt' => 'Circle Picture'))