Not sure where that post is but I'll give you a quick rundown on how to do it.
First go to the site where your pic is hosted
Open the pic to the largest size like you already did above.
Right Click and go to properties
Copy the url
Now for the part that's giving you the problems
insert your url between these
please note ... remove the space between the "g" and the "]", they are only there for demonstrating this technique
Happy Modelling and God Bless
Robert