searches for an image resource locally. I have no idea what happens when you pass it an external URL. image is probably nil. In the next step, .Destination (which is the image URL) is passed to relURL. This is most probably not what you want for an external URL:
Nor would absURL be sensible here – we’re talking about an external URL, so why would you want it to have any relation to your baseURL? Simply using .Destination | safeURL should be enough (I think).
While you’re at it, you might want to rework the “responsiveness” of the images. Providing a srcset without sizes might not make a lot of sense:
Also, please put ALL YOUR CODE in three backticks like so
``` code goes here
That makes it a lot (A LOT) easier to copy and prevents stupid thinks like curly quotes in code.