You want the RSS icon to appear automatically? You need to attach your FEED display to one of your page or block (etc) displays which are within the same view.
To do this:
In the FEED view, see
Feed settingsand click on
Attach to: Noneand select whichever of your previously created displays you want the icon to appear on (NB - you need to create other displays first if you haven't already done so).
Only then the RSS icon will be displayed on the page your feed is attached to.