Jeremy, links are case sensitive in general, but a Windows machine does not care. GitHUb probably uses a unix based OS and they are case-sensitive. Change the PNG to png and it should work.
Clemens
On 4. May 2017, at 16:42, Jeremy Tandy <jeremy.tandy@gmail.com<mailto:jeremy.tandy@gmail.com>> wrote:
All- Simon helpfully added a couple of images to the Spatial Things section [1] to clarify some points. Unfortunately, these aren't being served by GH-Pages. Works fine on my local version.
Anyone know why? Is it just a quirk of GH-Pages?
Thanks, Jeremy
[1]: http://w3c.github.io/sdw/bp/#spatial-things-features-and-geometry