Hello, Magento Buddies!
To help store merchants manage their catalogs, Magento supports a variety of product types by default. In the event that no swatch is selected, the parent product image is displayed. A user can also view the images of the related swatches when they select any swatch. When selecting a swatch, the parent product image of configurable products will be hidden from the product details page. Deep dive into hiding Configurable Parent Product Image from Details Page When Color Swatch is Selected.
Complete Tutorial at Hide Configurable Parent Product Image from Details Page When Color Swatch is Selected