I'm not going all "outrage culture" here--a picture doesn't tell me how long Conway was sitting zazen on her heels (shoes on the sofa) with her knees apart in a knee-length dress in a room full of people. It could have been the fleetingest moment as she took and checked her cell phone picture. But for ladies brought up a certain way, questions come to mind:
"Are you brand-new?"
"Were you raised indoors?"
"Are you part housecat?"
Which is how one's folks might have reminded you how not to sit in front of company. The reason some are registering dismay is partly because of their own home training, but also because of a recognition that manners reflect not just on oneself, but how one feels about the people surrounding one.
Not that anyone asked me.