Why It's Not That Crazy:
Look at Andy's cowboy hat above, aka one possible reason why he's so sad in the image, since it looks nothing like his favorite toy's hat. Now look at Jessie's hat:
And look at the hat on Emily's childhood bed (in the '60s or '70s):
Don't look at her boot lamp, though. We're calling dibs.
It's the same freaking hat -- passed to Andy from his mother, who apparently misplaced the white lace in the middle at some point, possibly after running out of TP in the bathroom one time (you can still see the faint imprint where it used to go, though). While we're at it, look at Andy's mom and Emily side-by-side:
If they're not the same person, Pixar's getting pretty lazy at character design.