It is definitely recommended herein that one concentrate his mind upon the form of Visnu. There are twelve different forms of Visnu, which are described in Teachings of Lord Caitanya. One cannot concentrate his mind on anything void or impersonal; the mind should be fixed on the personal form of the Lord, whose attitude is cheerful, as described in this verse. Bhagavad-gita states that meditation on the impersonal or void features is very troublesome to the meditator. Those who are attached to the impersonal or void features of meditation have to undergo a difficult process because we are not accustomed to concentrating our minds upon anything impersonal. Actually such concentration is not even possible. Bhagavad-gita also confirms that one should concentrate his mind on the personality of Godhead.