This type of breathing is mostly helpful to create awareness in how we breathe and as a stepping stone to learning yogic breathing. It is the common way many of us breathe which expends more energy than abdominal breathing.
To practice thoracic breathing one starts with breath awareness and then tries to focus on expanding the ribcage only, without using the diaphragm. The focus should be only on the expansion of the chest as one inhales and the contraction of the chest as one exhales.
Breathwork India 