PhotoDesktop is a lightweight utility that offers you the means to load multiple images at once and view them as a single item. It can come in handy for image comparison as you can open two instances of the same image and scale them differently.
The UI is split into two main parts, which are both displayed when booting the app. The first part is the toolbox, which is represented by the smaller window that contains the means of operation. You can close the toolbox at any time, but to re-open it, you have to check the context menu.
As for the second part, that is the big preview panel that allows you to scroll and scale the photo groups after you add them.
Adding photos can be done from the Images menu on the toolbox. After you select the images and add them, a preview model gets displayed in the small integrated tab. However, to migrate the group to the larger screen, you have to go to Views and click Add. Keep in mind that each new set has to be added through the Views tab, they won't go automatically.
If you intend to save an image formation and come back to it later, you should go to Projects and save the current session. At the same time, you can create multiple projects and add them for preview and/or comparison.
The Options menu is limited at three functions, which impact the background and the way you prefer to use your mouse. If we push aside the background color feature, which is already obvious, which leaves us with a reverse mouse zoom feature, that dictates the way your mouse wheel zooms in and out, and the scrolling method, which controls how you change a project's position.
PhotoDesktop is a simple tool that lets you create photo groups that can be moved to the larger panel where you can apply different levels of zoom to compare them. The interface is fairly intuitive, and if you spend a couple of minutes with the app, you'll quickly master it.