FastPreview is a free Windows app that allows you to easily visualize images, and it is an alternative to the image viewer that comes with Windows by default.
You can see the image in different sizes thanks to the zoom tool. You can also rotate the image if it doesn't have the correct orientation.
The program integrates with the contextual menu of the image file, offering a thumbnail preview. You can change the size of that preview in the app options.
Another feature of FastPreview is that it allows you to view more information about the image in the Details tab of the file properties window for the image that you want.