Having become Brahman, one is ever cheerful, does not grieve or crave for anything. Feeling equal towards all beings, he begets transcendental devotion to Me (the Supreme).
By the exclusive jnana-nishtha, when one attains and becomes Brahman, the whole discussion, being complete, should naturally stop. There will be no further addition or extension. But Krishna strikes a significant difference. He describes the Brahma-bhuta as ever cheerful, not given to grief or desire. Such sameness and evenness have been dealt with earlier in many contexts.
What is then the difference here? Earlier it was a pursuit, practice of a quality, wherein the seeker reflects his striving, by virtue of which he intends to reach somewhere. But here no such yearning or aim is fostered. Whatever transpires is a natural sequence, development. Just as when the shutter of a dam is opened, water gushes forth as a river, here too with the Brahma-bhuta something significant and tangible transpires. Even though he yearns not for any quality or attainment, he still becomes accomplished.
Krishna calls it transcendental devotion. The earlier stages imply deliberate efforts and practices. But here, without any effort or yearning, parā-bhakti (supreme devotion) springs and flows in abundant measure!
This bhakti makes one know the supreme Reality; what it is in essence, and what extent it has. Knowing the Supreme thus in essence, he enters into its domain with all ease and felicity!
The entry into the Supreme is not a physical process or a result of any particular action or procedure. It is a fruition that takes place effortlessly, as a natural consequence of the knowledge the seeker gains. He understands the whole world to be a direct display of the Supreme. And in that extensiveness, he, as an individual, already reigns. Yes, he is one with the Supreme. No further entry is necessary.
Entry is effected by the knowledge his intelligence gains. It is all knowledge, and knowledge alone!