Karmaṇā daiva-netreṇa (SB 3.31.1). By superior arrangement. You cannot say that "I want this kind of body." God is not your order supplier. You'll get. Either you ask for it or don't ask for it, you according to your karma, you'll have a next body. Karmaṇā daiva... By the superior arrangement. If you work in this life like God you'll get next life a god's body. And if you work in this life as a dog then you get next the life as a dog. That is not in your hands. Prakṛteḥ kriyamāṇāni guṇaiḥ karmāṇi sarvaśaḥ (BG 3.27). Guṇaiḥ. According to your qualities, as you will work, and prakṛti, nature, will give you a similar body.
Otherwise, why do we find so many varieties of bodies? So many varieties. Just like so many varieties of apartment, so many varieties of hotels, so many varieties of appointment. So you are appointed, you are put into an apartment, or hotel, according to the terms of your payment. That is karma. So you cannot say everything is also equal. That is nonsense. They cannot be equal because we are working under three qualities, goodness, passion and ignorance. If we work, field of activities... This, this body is field of activities. Nobody can work similarly because they have got field of activities different. My body is different, your body is different. You are acting according to your body. The hog is acting according to his body. The dog is acting according to his body. The president of some country is acting according to his body.
So we should have brain to understand that: "Why there are different personalities and different activities? Because there are different qualities. So to organize human society these qualities should be taken into consideration. We should divide. Just like in our body we have got four departments. This head department, the arm department, the belly department and the leg department. Everyone is working according to the departmental function. The brain is working differently. The office or the direction, the brain is giving direction. Then my hand is moving, my leg is moving. Similarly, there must be a directory department. In office also there are board of directors, then secretaries, then clerks, then menials, then servants, then cāparāsi. So even in your body this arrangement is there.