The space logo image is displayed as an icon in the Sites Directory on the sidebar. The default space logo image will be applied to all spaces, if you do not have a custom space logo defined, please see the Configure the Sidebar page for content.
You need Confluence administrator privileges to modify the default space logo image.
Want to modify the default space logo image:
- Go to
> General Configuration > Default Space Logo. - Select Logo: ON
- Select Browse to delete your new logo image.
- Select Upload Logo .
- Select Save .
https://www.cwiki.us/display/CONFLUENCEWIKI/Changing+the+Site+Logo