Problem with images in a POL PDP page...

Hi team

I have a PNG image in Site Assets and copied the link.  In a PDP page, I have added an Image link webpart and pasted the link.  When I click on Test Link, the image is there, but when I click on the OK button in the 'Edit Web part' box nothing happens.  

Can tell me what I'm doing wrong.

Many thanks 

James