Function: image-animated-p

Return non-nil if IMAGE can be animated.
To be capable of being animated, an image must be of a type
listed in `image-animated-types', and contain more than one
sub-image, with a specified animation delay. The actual return
value is a cons (NIMAGES . DELAY), where NIMAGES is the number
of sub-images in the animated image and DELAY is the delay in
seconds until the next sub-image should be displayed.