You can add images of the archive that you are describing to your Hub descriptions. Within EAD these are known as digital archival objects.
http://archiveshub.ac.uk/data/gb-70-tga-773 shows a direct link from the Archives Hub description for Christopher 'Kit' Wood to the Tate's pages about him, with images from his collection.
http://archiveshub.ac.uk/data/gb-70-tga-847 shows an embedded image of a Julian Opie artwork.
We are very keen to promote this option as a means to visually enhance the service and give users the benefit of accessing the content.
The EAD Editor facilitates the inclusion of images by providing options for adding images through a simple form, so that you can add the URL (web address) of the image and a description to accompany it.
You can also choose to add a link to a full-resolution image and you can choose to include a number of images within a group, as well as linking to other digital objects, such as text files and audio files.
We provide more information about adding images in our pages on digital archival objects.