Figure in github.io stretched by gh-pages or w3c stylesheet/jscript ?

Folks - 

As you know (!) I have been working on a document describing extensions to SSN for observation-collections and for ultimate-feature-of-interest. 
The draft can be viewed here: https://w3c.github.io/sdw/proposals/ssn-extensions/ 

You will see that the figures are stretched horribly :-( 
I can't figure out what's causing this. 
It started happening just a few weeks ago - earlier versions rendered fine. 

The source is here: https://github.com/w3c/sdw/blob/gh-pages/proposals/ssn-extensions/index.html 
The relevant <img> elements have nothing to adjust the size, 
but height="2765" width="1781" are being injected somehow when it is rendered, I can't figure from where? 

My HTML/css/jscript skills peter out at this stage. Any insights folks? 

Simon 

Received on Monday, 21 May 2018 23:00:07 UTC