Allways the same missing information:
- OS you are working on.
- Version of InDesign
- What kind of EPUB export. Settings?
1. Windows 8.1
2. The latest update from Creative Cloud,
3. Reflowable, and since there are about 800 settings, I will assume you are asking purely about the object export settings, though, presumably, since there are no object-level settings on this graphic it should be outputting the same as all the others.
What version EPUB did you export as? Does it work as an EPUB from InDesign to other EPUB readers before the MOBI conversion?
If so, this is not an InDesign issue.