This is probably a very big observable difference between bodybuilding and physique.

Bodybuilders tend to rely more on muscle mass as compared to the people into the physique. Due to more muscle mass, the body is lesser attractive as compared to Physique. There is more of vascularity i.e. appearance of veins on the muscle surface which is one of the reasons for the muscles to lose grace.

Another difference that strikes due to larger muscle mass is the midsection of the body i.e. the waistline.  Bodybuilders, due to rigorous workouts, tend to develop waist muscles as well which leads to larger and bulgier waistlines.

On the contrary, Men’s Physique athletes have very narrow waistlines. They cut down incredibly on their body fat content to get a conditioned and yet a narrow physique. A bulged waistline is an acceptable trait in Bodybuilding but not in Physique.