You can upload your organization's logo on the Logo page to better associate your website with your organization.
Not all of the website layouts support a logo.
In order to see your logo on your website, you must first upload a logo, then enable the logo on the Website Settings page.
Where do I find it?
You can find the Logo page by going to Website > Logo.
The logo image must be at least 200x200px in order for Facebook to use the logo as your website's image. See the following Facebook web page for more information about your organization will appear on Facebook:
Overview
Content Tools