Sharing to Facebook currently just adds an image of the song's album art (a little overly obtrusively watermarked, IMO) to a Facebook gallery — none of the post's content comes along with it. Sharing to Twitter at least preserves some of the caption (truncated of course).

It would be great to have the caption shared as well as the album art — ala Instagram — so there's some context to it, as well as a link for others to listen to the shared song.