• dundubhayaḥ — kettledrums
  Dundubhi — the celestial drum sounded at all great Vedic moments: gods' victories, royal coronations, the Lord's līlās. The drum's sound from divi establishes the deva-loka's blessing on the union.
• jaya - śabda — the sound 'victory'
  Jaya (victory) + śabda (sound). The single Sanskrit cry that runs through the entire Bhāgavatam at moments of līlā: jaya, jaya. Gauḍīya kīrtana inherits this; every saṅkīrtana is an echo of dvāpara's jaya-śabda.
• kusuma - āsārān — torrents of flowers
  Kusuma (flower) + āsāra (downpour). The standard celestial response — Brahmā showering flowers when Kṛṣṇa lifts Govardhana, the gods showering flowers at Rāma's coronation. Heaven has no other gift it can offer: it gives flowers.
• harṣa - vihvalāḥ — overwhelmed with joy
  Harṣa (joy) + vihvala (overwhelmed). The gods themselves are tossed by their own ānanda. Gauḍīya rasa-theory: even demigods experience secondary bhāva at the Lord's victories, though their stable rasa is reverence.
• devāḥ — demigods
  Deva — the heavenly administrators. They do not marry Lakṣmaṇā themselves (verse 17: she rejected the loka-pās), but they bless the bride who saw past them to Mukunda. Their flower-rain is the higher beings' acknowledgement that the Lord's bride chose rightly.

• What recent victory of mine deserves wider rejoicing than I have allowed?
• How could I let the multiple worlds' applause in?

The cosmos itself recognizes the moment: drums sound in heaven, the people shout victory below, demigods empty their petal-baskets. The same celestial response that greets every great līlā — the gopīs' first dance, Govardhana lifted, the demons slain — pours down here too. The marriage is being ratified above before the bride has even garlanded.