Lord Balarama was able to see, with the eye of transcendental knowledge, that all these calves and Krsna's friends were expansions of the form of Sri Krsna - SB 10.13.38

Expressions researched:
"Lord Balarāma was able to see, with the eye of transcendental knowledge, that all these calves and Kṛṣṇa's friends were expansions of the form of Śrī Kṛṣṇa"

Srimad-Bhagavatam

SB Canto 10.1 to 10.13

Lord Balarāma was able to see, with the eye of transcendental knowledge, that all these calves and Kṛṣṇa's friends were expansions of the form of Śrī Kṛṣṇa.

SB 10.13.38, Translation and Purport

Thinking in this way, Lord Balarāma was able to see, with the eye of transcendental knowledge, that all these calves and Kṛṣṇa's friends were expansions of the form of Śrī Kṛṣṇa.

Every individual is different. There are even differences between twin brothers. Yet when Kṛṣṇa expanded Himself as the boys and calves, each boy and each calf appeared in its own original feature, with the same individual way of acting, the same tendencies, the same color, the same dress, and so on, for Kṛṣṇa manifested Himself with all these differences. This was Kṛṣṇa's opulence.