This is the specialty of Gaudiya Vaisnavas, which is not there in any other sampradayas. The feeling of bosom relationship of this world [laukika sat-bandhu]. Like, Krsna is my beloved. Krsna is my friend. Krsna is my son. This worldly mood will exist. However it is not worldly. It is transcendental. Krsna is also transcendental. The devotee is also transcendental. But towards Krsna, one will possess a mood like an intimate relationship of this world. Otherwise vraja-prema cannot become realised.
And without this worldly mood [of ‘He is mine’ towards Krsna], one cannot attain Krsna in that form. Ultimately, the aim, the desirable and worshipable object of Gaudiya Vaisnava acaryas is the mood of Vraja.