Yes. That is the way all their heads are shaped.
Not all Chi's have "Apple Heads". Some have a slimmer profile called a "Deer Head or Deer face". Apple Head represents the round dome and forhead of the their head, making the head look like a little apple. Most Apple Heads have shorter noses too, making their heads look even bigger. The Deer Headed Chi's have a bit longer nose and a slimmer head, not so round.
Yes, the apple head Chihuahua has the domed head and shorter snout. This is the standard for the breed. This is how a Chihuahua is supposed to look. The deer head Chihuahua came about from breeders breeding inferior dogs and they came up with the name "deer head" to make them seem like something special, they are really just a poor quality dog and do not fit the standard for the breed.