Move PhotoImage

[Gribouillis]

I think you need to do

self.item1 = self.canvas.create_image(self.player1_x, self.player1_y, anchor=NW, image=self.player1)
...
self.canvas.move(self.item1, self.player1_x, self.player1_y)

the PhotoImage instance and the canvas item are two different things.