The last song I heard was Never Been In Love by Will Jay. (Quite fitting, I know ^^; I was checking out romantic posts on tumblr and stumbled across it and I love it!!)
Edit:
If you're asking how does the thumbnail of the video appear, then I just copy-pasted the youtube link and it appeared by itself. I didn't use the link option to insert the video's link, I just copy-pasted it.