Ok, sorry for trying to paraphrase your simple question. I use a Mac when I post here so all I have to do is pull up the individual post, highlight the address, then hit the copy function. Then I can come over to the window here, paste it and iLube does the rest for me. Like this one here....
It's just like copy and pasting any other link. Up until a couple years ago, only the link would post so we had to click on the link to see it. These days the links automatically embed into the post so folks who don't have a Twitter account get to see the videos too.