All the Viṣṇu forms had four arms, with conchshell and other articles, but these characteristics are also possessed by those who have attained sārūpya-mukti in Vaikuṇṭha and who consequently have forms exactly like the form of the Lord. However, these Viṣṇu forms appearing before Lord Brahmā also possessed the mark of Śrīvatsa and the Kaustubha gem, which are special characteristics possessed only by the Supreme Lord Himself. This proves that all these boys and calves were in fact directly expansions of Viṣṇu, the Personality of Godhead, not merely His associates of Vaikuṇṭha. Viṣṇu Himself is included within Kṛṣṇa. All the opulences of Viṣṇu are already present in Kṛṣṇa, and consequently for Kṛṣṇa to demonstrate so many Viṣṇu forms was actually not very astonishing.
The Śrīvatsa mark is described by the Vaiṣṇava-toṣaṇī as being a curl of fine yellow hair on the upper portion of the right side of Lord Viṣṇu's chest. This mark is not for ordinary devotees. It is a special mark of Viṣṇu or Kṛṣṇa.