Delete Original Image is a WordPress plugin to delete the the original image file uploaded.
The problem that solves, is that the original image file is usually huge (can be >6MB if it is a photograph) and it is never published on the pages, so there is no need to keep it on your server, and it it a must to delete it, if you have limited storage space and you are uploading tons of pictures.
The plugin gives you the option to enable/disable this, to be done automatically when you upload an image.
And/or you can do it in bulk for all your previously uploaded images.
Specifically, this plugin copy the ‘large’ image ( i.e: your-pic-1038×576.jpg ) to the original file path ( i.e.: your-pic.jpg ).
Nothing should brake, all other plugins should keep working, but you need to know that the original image is no longer available on your site, so please do a backup if you think you may need the original images in the future.