You have html code inside the image. What you need is just the url.
[IMG]<iframe src="http://giphy.com/embed/uptVBemKNYvU4?html5=true" width="480" height="259" frameBorder="0" webkitAllowFullScreen mozallowfullscreen allowFullScreen></iframe>[/IMG]
The iframe stuff in there is not compatible with the img bbcode!