Some newer airline seats (not limited to Asian carriers) have steps built into the side of the aisle seat, presumably specifically to help shorter people reach the overhead bins. In the example below, the aisle seat with the step is on the right side of the image (but would be on the left side from the point of view of someone sitting in it).
Wow, this would be very handy for me too on larger aircraft—on 767s etc., I often have to stand on (my own) seat to rummage around in my bag during the flight or to grab hold of it if it’s slid to the deep end of the bin out of my reach. I always sit on the aisle and (as I tend to board early) put my bag above my own seat, so fortunately, I’m not stepping on anyone else’s seat to do this.