SB 3.28.33

dhyānāyanaṁ prahasitaṁ bahulādharoṣṭha-
 bhāsāruṇāyita-tanu-dvija-kunda-paṅkti
dhyāyet svadeha-kuhare ’vasitasya viṣṇor
 bhaktyārdrayārpita-manā na pṛthag didṛkṣet
Synonyms: 
dhyāna-ayanam — easily meditated upon; prahasitam — the laughter; bahula — abundant; adhara-oṣṭha — of His lips; bhāsa — by the splendor; aruṇāyita — rendered rosy; tanu — small; dvija — teeth; kunda-paṅkti — like a row of jasmine buds; dhyāyet — he should meditate upon; sva-deha-kuhare — in the core of his heart; avasitasya — who resides; viṣṇoḥ — of Viṣṇu; bhaktyā — with devotion; ārdrayā — steeped in love; arpita-manāḥ — his mind being fixed; na — not; pṛthak — anything else; didṛkṣet — he should desire to see.
Translation: 
With devotion steeped in love and affection, the yogī should meditate within the core of his heart upon the laughter of Lord Viṣṇu. The laughter of Viṣṇu is so captivating that it can be easily meditated upon. When the Supreme Lord is laughing, one can see His small teeth, which resemble jasmine buds rendered rosy by the splendor of His lips. Once devoting his mind to this, the yogī should no longer desire to see anything else.
Purport: 

It is recommended that the yogī visualize the laughter of the Lord after studying His smile very carefully. These particular descriptions of meditation on the smile, laughter, face, lips and teeth all indicate conclusively that God is not impersonal. It is described herein that one should meditate on the laughter or smiling of Viṣṇu. There is no other activity that can completely cleanse the heart of the devotee. The exceptional beauty of the laughter of Lord Viṣṇu is that when He smiles His small teeth, which resemble the buds of jasmine flowers, at once become reddish, reflecting His rosy lips. If the yogī is able to place the beautiful face of the Lord in the core of his heart, he will be completely satisfied. In other words, when one is absorbed in seeing the beauty of the Lord within himself, the material attraction can no longer disturb him.