virtuexru

This plugin will allow you to add one image or logo of your choice (defined in settings) 
to your RSS feed header. It is very simple to install/maintain and will add your website’s 
presence to your RSS feeds by giving it this personal touch.

RSS Add Image Header

This plugin will add an image/logo of your choice to all of your RSS feeds.

Mark Jaquith

This plugin allows you to customize the logo on the WordPress login screen. There is zero configuration. You just drop the logo file into your WordPress content directory, named <code>login-logo.png</code> and this plugin takes over.
Note that you should use a transparent background on the PNG image, crop it tightly (no padding pixels) and use a width of exactly 312 pixels for best results. Wider images will be downscaled in modern browsers, but it isn’t recommended to rely on that.
This plugin also works in the <code>mu-plugins</code> directory.

Login Logo

Customize the logo on the WP login screen by simply dropping a file named login-logo.png into your WP content directory. CSS is automatic!

RSS Add Image Header vs Login Logo