First of all, every party not in the White House likes to express shock and outrage at the way the other side is treating this hallowed job and office. Republicans were incensed when Bill Clinton and Barack Obama treated the Oval Office with slightly less formality than did Ronald Reagan, who, famously, always wore a suit coat in the Oval Office.
Obama puts his feet on the desk! Obama throws a football!
This is all par for the Internet outrage/partisan police.
It was dumb when Republicans leveled the charge of Obama and Clinton disrespecting the White House. It is equally dumb now.
Then there is the specific context of the photo above. While not captured in most of the photos that initially circulated on the web, other snaps of the moments following the initial picture show that Conway just trying to get in position to take a photo of the gathering.
Anyone who has ever tried to take a big group picture can sympathize.