Images view can be found in 'Content>Images'. Images for a GrandVision banner should only be added in its own folder. Like images for MultiOpticas should only be placed within the MultOpticas folder. As an editor you're free to create folders and images as you see fit.
When you upload an image, a set of image variants will be created. A thumbnail, original and a mobile variant. In some cases you would like to show a different image when you're viewing the website on mobile. In that case you can edit the image and select a specific mobile image to upload.
Also don't forget to add a description on your image.