Here is my test case.
http://tobeythorn.com/isi/dummy2.svg
http://tobeythorn.com/isi/isitest.html
If I just open the svg by itself, the inne
All SVGs used as images must be complete in a single file. Images cannot load external data.
So you need to base64 encode the image and embed it into the SVG as a data URL to get it to work.