This is a wordpress plugin that allows the user to specify two images to display on the sidebar for a given page.
For the easiest install, download the zip in this repo and install it via the plugin manager in wordpress.
You can also place the entirety of the image-sidebar folder in the %YOURWORDPRESSDIRECTORY%/wp-content/plugins/
folder.
Install the plugin then drag it into your sidebar via the widgets page. Input a page slug and some images and hit save. This slug represents the page on which you want to display images. Once you hit save the widget will allow you to add more to it. Once values are saved, the widget also displays a preview image.