CC BY-SA, LGPL and GPL are all copyleft licenses. GPL's key feature is that by embedding one work in another (as defined in a software context), the combined work becomes GPL. With LGPL this is not the case.
My understanding is that if I embed a CC BY-SA work in something, say a photo in an article or a song in the background of a video, the work does not have to be CC BY-SA, it could even be restricted (as long as attribution is given). So in this way would it be more accurate to compare CC BY-SA to LGPL rather than GPL?
(I assume that a music video of a pre-existing song would be a derived work, but a slideshow with background music would be a combined work. For the purpose of this question let's assume the distinction is clear.)