ArcVieh

You can select images from media Library in the Widgets backend that will be shown on your Page. You can enter a size for the images.
The thumb-images will be linked to the full-sized-image. 
Requieres PHP 5!

Media Images Widget

Requieres PHP 5! You can select images from media Library in the Widgets backend that will be shown on your Page.

Hiranthi

onexa

By default WordPress lets you take quite a few steps for adding images from your media library to your blogroll items (links). This plugin simplifies that process.
After enabling you’ll find the upload icon at the Image field (Advanced block). Click that to select the image you would like to use for that particular link.
Don’t have the image in your media library? No problem! Since it’s using the built-in media uploader screen you can easily upload images from the spot!
Found the image you were looking for? Click the “Add to post” button and the image is automatically added to the image input-field.

Easy Blogroll Image

Easily add media library images to your blogroll items (links).

Media Images Widget vs Easy Blogroll Image