This is illustrated for linking to the RIL, but the principle is the same for linking to any thread.
I work with two Internet windows open - it's less confusing!
Here it is in pictures
In one window open the RIL to the image you want - your lily by snowgoose -
and highlight and copy the url
In another internet window, open the emergencies thread (so you have two internet windows open) and go to the reply box
Then click on the globe icon and this window comes up - you'll see I've pasted the url into the script prompt box
click OK and you'll get this -
this is when you simply type your word - e.g. Macro of yellow lily by snowgoose
Take the cursor to the end of the line of text so you don't split your link - bettter still, to a new line and repeat the process with your next image in the Lib.
Because you keep a separate window for the Emergencies thread, you can change images in the Library easily.