You can select an area of the web page using the Capture search mode. The search mode can be set independently for the context menu and the browser toolbar from the extension's options.

You could also enable the "Use deep search when selecting images" option to continue searching with the Select URL or Select Image search modes. When enabled, the extension extracts all images from the clicked area, even if an overlay image was immediately found. If multiple images are found, you can select the one you need from a popup that lists the images along with their dimensions.