animated image element
The xlink:href of an image element is animated.
The random generated images cover a blue circle.
The image element has an opacity of 0.6 and
a type of image/gif is given. The server
serves an empty Content/Media/MIME type.
Therefore the type given by the animation of
the type attribute is relevant.
The visible effect is a blue circle covered with
the image with an opacity of 0.6. Because the
image is never empty, there will be always the
blue circle and the image visible.
To check, whether the hint is interpreted at
all, the small image top left has an animation
with the wrong types. If the hints are followed
this cannot result in a useful display of the small
image. Bottom right the type authoritatively given
by the server is wrong, that of the type attribute is
right. The server information should not result in
a useful display, because this should not be ignored.