[ All Haruka's pictures are of good moments (if you can apply that qualifier to things like "the day she nearly ran two of her fellow soldiers over on a motorcycle"). But that, in its own way, taunts Haruka just as much as if the Wardens had captured more heartbreaking scenes. It implies they've always been watching.
Despite this, she tries a smile. ]
Think of it this way! If everybody's looking for their bad memories, nobody will have time to spend on yours.