title_body: Why are lattes often served in big, wide cups?
upvoted_answer: It may be just me, but I think it has to do with aiming for a ratio of foam to liquid in each sip.
  
  Basically a taller cylindrical cup with the same amount of foam on it would cause the first couple of sips to be mostly, if not entirely, foam. With a shorter wider cup you can have a lot of foam, but in a thinner layer, allowing for a more balanced sip and better mouth feel through the duration of the cup.