Focal point based image cropping for EPiServer using ImageResizing.NET

https://world.episerver.com/blogs/stephan-lonntorp/dates/2016/9/focal-point-based-image-cropping-for-episerver-using-imageresizing-net/

Does anyone have information how to use this plugin. Simply installing it and creating a ImageFile media type does not seem to do anything.

[ContentType(DisplayName = "ImageFile", GUID = "nquid", Description = "")]
[MediaDescriptor(ExtensionString = "jpg,jpeg,jpe,ico,gif,bmp,png,svg")]
public class ImageFile : FocalPointImageData
{
        /// <summary>
        /// Gets or sets the copyright.
        /// </summary>
        /// <value>
        /// The copyright.
        /// </value>
        public virtual string Copyright { get; set; }
        [Editable(false)]
        public virtual string FileSizeKb { get; set; }
}

When implementing I've tried:

[Display(GroupName = SystemTabNames.Content, Order = 10)]
[UIHint(UIHint.Image)]
[CultureSpecific]
public virtual ContentReference MainImage { get; set; }
//
[UIHint(UIHint.Image)]
[Display(GroupName = SystemTabNames.Content, Order = 10)]
public virtual Url SiteLogotypeUrl { get; set; }

If you read this: https://github.com/defsteph/EPiFocalPoint

It's just supposed to work...