This is not a new thing, it appears since many years ago when the dial-up line still common among houses.
To be honest, I only know this kind of picture call ‘Progressive JPEG’ since today, although this kind of JPEG has been so popular since last time and fade out in recent years as the connection is more faster now.
I always prefer things that work under limited resources such as this one.
Ok, I admit that I read a very brief intro about this kind of JPEG here, that made me think better to write it down somewhere in my blog:
Great understanding with sample pictures in there!
Keywords: Slow internet connection, picture, graph