I got in touch with BAILLI after reading your post. Their chief exec said:
"There are many judgments on BAILII which contain images including diagrams, tables and photos. Most often these are in the following courts (I’ve given one example, of many possible, for each):
Technology and Construction Court:
Ocensa Pipeline Group Litigation, Re  EWHC 1699 (TCC) (27 July 2016) http://www.bailii.org/ew/cases/EWHC/TCC/2016/1699.html
Intellectual Property Enterprise Court:
T & A Textiles and Hosiery Ltd v Hala Textile UK Ltd & Ors  EWHC 2888 (IPEC) (23 October 2015) http://www.bailii.org/ew/cases/EWHC/IPEC/2015/2888.html
Merck Sharp And Dohme Ltd v Shionogi & Co Ltd  EWHC 2989 (Pat) (25 November 2016) http://www.bailii.org/ew/cases/EWHC/Patents/2016/2989.html
There are instances of images in all of the UK courts covered by BAILII along with many from the European Court of Justice also on BAILII. Note that many of the commercial legal publishers never had images, diagrams, tables or photos included (even when they were crucial to understanding the judgment)."
So there you go.
And of course there was the emoji judgment, which gave me the opportunity to mock up an excellent kids' book: http://www.rollonfriday.com/Default.aspx?TabId=58&Id=4771&fromTab=58¤tIndex= 82