my toe clips are almost identical to this :
although I ride with them fairly loose, it's still not loose enough to bend on the up stroke... it's almost like a horizontal oval shape if that makes any sense - just like it is in the picture....
on the up stroke, the part of my foot that propels my peddling motion is the area before my toes and after my ankle. i use my toes a little but the motion that i use on the upstroke is like walking up stairs - i am literally lifting my entire leg (and foot) up with my quads.