Sharing a single Chrome browser tab works a little differently than sharing a single window or your entire screen. It is an especially useful method if you want to share video or animation during your meeting. First, you need to be using Chrome, since it's the only browser this method of sharing supports.
Click Present now.
Select A Chrome tab.
Select a tab from the list.
Click Share.
Now, just that browser tab is shared, and none of the other parts of the window are included. The screen sharing notification appears inside the browser window as well.