Alexa Image URL

So the alexa addon is fantastic, but the Image URL has me stumped.

sometimes it will give a good image like…

But other times it will give a huge string that is not an image (I x’d out some of it as it may have sensitive information in it) this does not end in a .jpg

Any idea why this is, how do I get a good jpg image every time?

They’re just URLs. They can point to anything.
My quick read of the Alexa binding documentation seems to indicate there’s no configuration for the image url channel, so you’re pretty much stuck with whatever it sends.