For linking your layout from the gallery you will have to do 2 steps.
Basically it's easier to use two tabs. One for your layout in the gallery and one for the post/thread.
1. Right click on the gallery layout and choose COPY IMAGE LOCATION
1a. Go to the thread, paste in between this code: [img][/img] so it would go between the opposing ] [ brackets with no spaces.
*** it will look like this [img]
www.myimagelocation.com [/img] without the spaces
2. Copy the gallery URL in the address bar
2a. Highlight the full image text including the parts ([img][/img]) , once highlighted use the "WORLD" icon and in the pop up paste the url link, click ok.
Your layout will be pasted and linked to the gallery.