per physical appearance 

In regards to your question about adding more pictures, one of the main concerns of editors on the MJ page is that the pictures are cluttering up the text and making it more difficult to read. I would have to agree with this concern: as nice as pictures are, wikipedia is about information and this is conveyed through text and to-the-point pictures. I think that putting pictures documenting the change in Michael's appearance would draw undue attention to that facet of his life. Sure, a few pictures are good, but these show him in some important light, whether in a record-breaking video, or on the cover of one of his record-breaking albums, or during a popular performance. That leads me on to your other query, about using images from live, recent events. The only problem there is that, IMO, the picture quality decreases and that brings recentism to the article. Basically, it's focussing too much on the present, whereas wikipedia is meant to equally document MJ's entire life. Finally, regards the 80s picture, I was actually against it a while back, and tried to replace it with a then-recent picture of his acceptance of a 'Legend Award' in Japan. I didn't manage this successfully, but then I realized that the current picture is probably the best one to be there. It is the perfect representation of MJ, in the prime of his career, epitomizing the success that he was, and IMO still is. To put a 2007 picture would bring recentism to the article, and most editors don't like that. Anyway, I hope that I've answered some of the queries you have. If you need to know anything else just contact me on my talk page. Thanks.