could the pair "jpg + jpeg" be considered as the similar image type?

please take JDK-8133847 test example and define:

    private static final String IMAGE_NAME_1X = "image.jpg";
    private static final String IMAGE_NAME_2X = "image@2x.jpeg";

Output (Mac OS X 10.10.3, JDK9 b77):
  file: /Users/xxx/work/tests/Test1/image.jpg
  image class: sun.awt.image.ToolkitImage
  Exception in thread "main" java.lang.ClassCastException: sun.awt.image.ToolkitImage cannot be cast to sun.awt.image.MultiResolutionImage
        at Test.main(Test.java:27)