SB 3.28.33

The yogi is recommended to visualize the laughter of the Lord after studying His smile very minutely. This particular description of meditation-smiling, laughter, face, lips and teeth, everything very particularly means that there is no case for impersonalism. Everything, personality described from one point to another. That is the business of yogi's meditation. Another exceptional description in this verse is that the laughter or smiling of Visnu should be meditated upon, not that one can manufacture by his imagination of something else besides the form of the Lord. Because except the smiling and laughter of the Supreme Personality of Godhead, no other such activity can completely cleanse the heart of the devotee. The exceptional beauty of laughter of Lord Visnu is explained that the teeth, the small teeth resembling the buds of jasmine flower becomes at once reddish on account of the reddish lips of the Lord. And if the yogi is able to place in the core of his heart such beautiful face of the Lord, then he will deny to see anything more beautiful in the material world. Or in other words, when one is absorbed in seeing the beauty of the Lord within himself, the material beautiful attraction can no more disturb him.