What is the icon on the far right of the screen?

What is the icon on the far right of the screen?

The icon on the far right of the Dashboard is the Lead Origin.  The Lead Origin is another layer of tracking independent of the Lead Source and Lead Campaign.  The Lead Origin icon can be hovered over to reveal if the lead was manually loaded, captured via email, or loaded via an API.  You can also use the Lead Origin filter to narrow down your leads by these options.