It is said that Lord Vishnu, appeared riding a fig leaf floating upon the tumultuous oceans after the dissolution has taken place, was the only one to survive the great catastrophe. He wished to recreate the world and when he so wished, there sprouted from his navel a lotus stem with a lotus on its top. Upon the lotus there appeared Brahma, the creator of the universe. The four headed Brahma carried in his four hands the four Vedas. The painting depicts Brahma rising from Vishnu's navel riding a lotus.
Just below the right arm of Lord Vishnu there are two demons. They are Madhu and Kaitabha who had won the boon of immortality after rigorous penance. There are different annals of their mystic origin but most of them relate to Vishnu. It is said that they wanted to eliminate Brahma and thus stop the process of creation. But Brahma had his seat upon Vishnu's navel. Hence, without disturbing and displeasing Vishnu they could not reach Brahma. Finally they one day reduced themselves to small insects and entered into Vishnu's ear and therefrom passing through the veins of the lotus stem reached Brahma but before they could do him any harm Vishnu woke up and caught hold of the two demons and crushed them between his thighs. With the fat that emitted from their bodies Vishnu smeared the earth which greatly added to its fertility.
The legend has been represented somewhat differently in Devi Bhagvata. Madhu-Kaitabha grown quite powerful after the boon of immortality from Devi stole Brahma's Vedas and harassed him in various other ways. Brahma made a complaint to Vishnu. A conflict between Vishnu and the two demons, hence, ensued but it only tired Vishnu whereas the demons kept as fresh as ever. Under a fool proof strategy when Madhu combatted with Vishnu Kaitabha took rest and when Kaitabha fought Madhu rested. Ultimately Vishnu approached Devi and asked her how he could kill the two demons. Devi told him that they could not be killed in direct combat and that he would have to kill them only deceitfully. Vishnu went to the demons and said that he was pleased with their prowess and they could hence ask for any boon from him. The conceited demons laughed and said that they were more powerful than him and, hence, he could ask them for any boon instead. This was what Vishnu had anticipated. He asked them to tell him how he could kill them. Nonplused demons bound by their pledge had to tell Vishnu how he could kill them. Adopting the same strategy Vishnu killed them.
As the other tradition has it, on Devi's advice Vishnu transformed himself into Mohini, the tempting maid, and fell on their way. Tempted by her unparallelled beauty they ran after her and beseeched for marrying them. Vishnu in disguise as Mohinin agreed but only after they gave her whatever she demanded as the condition of marriage. They accordingly promised. Mohini asked them to give her their heads. The unthinking demons took their swords and dethroated themselves and thus were eliminated.
This description by Prof. P.C. Jain and Dr Daljeet. Prof. Jain specializes on the aesthetics of ancient Indian literature. Dr Daljeet is the chief curator of the Visual Arts Gallery at the National Museum of India, New Delhi. They have both collaborated on numerous books on Indian art and culture.