I don't care who you are, leggings are not pants.  I don't know who started this horrid trend, but it's disgusting.  Nobody wants to see your hiney.  
 The cropped denim vest makes this look simply unbearable.  
 I don't care how pregnant you are...
 ...how skinny you are...
 ...how nasty you are...
...how stylish you think you are...
LEGGINGS ARE NOT PANTS!!!  They are leggings, to be worn under a dress, tunic or long shirt.