The Media Settings controls how your media is displayed.
You can change these settings at any time by going to Settings > Media, make your desired changes and then click Save Changes.
Your blog automatically resizes your images to three different sizes: thumbnail; medium and large. Most people keep these as per the default settings.
Delete large images
By default, delete large image is selected on all newly created blogs to automatically resize images when they are uploaded to your blog. This helps reduce your storage space usage and ensures that the images are optimised for viewing online.
You uncheck ‘Delete large image’ if you want to be able to click on a larger images without them appearing as cropped.