[Tkinter] PhotoImage and Jpeg images.

[Gribouillis]

So why has it never been updated to handle JPEG images?

It seems very plausible that it was not updated because one only needs two lines of code to handle JPEG images by importing PIL. Not updating the PhotoImage class for jpg means zero maintenance for the python team. It avoids duplicating existing functionalities. In fact it only penalizes people who refuse to install PIL. This may be too little motivation for the python devs...