Again based on the book The Tirumala Temple.

It looks like there are four types of Vishnu idols according to Agama Sastras – Yoga, Bhoga, Vira, Abhicharika. Bhoga Murti indicates wealth and should be installed in a village. Vira Murti is installed at the outskirts of a village and is used as a guardian deity. The other two, one for meditation and the other for destruction of enemy are installed outside the habitations. Any of the last three, if installed in a village will lead to it’s destruction. For each of them, there are three different types of postures – Sthanaka(standing), Asana(seated) and Sayana(sleeping). And then, based on the accompanying idols, there are three different types – Uttama(surrounded by Brahma, Maheswara and other deities), Madhyama(Brahma and Maheswara only) and Adhama(the idol stands alone). Combining all the three, there are a total of 36 different types of Vishnu idols which are used for prayer. But, the Abhicharika version has only Adhama form.

The idol of Lord Venkateswara is decked with ornaments and the upper two hands hold Sankha(left) and Chakra(right). The lower two hands, the right one is in Varada posture and the left one is in Katyavilambita(left hand resting on the thigh) posture. Sankha and Chakra are detachable and Sridevi is a part of the body, with the image present on the chest. Comparing,

  1. The idol is not a Bhoga Murti because that area never had an established inhabitation. Well, this is slightly shaky because the temple is under the domain of Tiruvengadakottam, with the fort on or near the main hill creating a possibility that the idol is the patron deity of the Governorship. Even if it is, the idol is not a Bhoga Murti because the hands are not in Abhaya posture and Sankha and Chakra are detachable.
  2. The idol is not a Vira Murti because the Sankha and Chakra are detachable
  3. The idol’s pose is similar to that of an Abhicharika Murti but it is not because an Abhicharika Murti is noted by it’s shrivelled body parts, a shrunken chin and eyes turned upwards.
  4. The idol is not a Yoga Murti because the lower right hand is in a Varada posture, not Abhaya.

Added to this, the presence of Sridevi, embedded into the body(it’s not a removable ornament) complicates the matters even further.

If it doesn’t fit any of the Agamasastras, does the sculptor carved the idol in the image of Parabrahma? It is said that the Parabrahma has five weapons, is symmetrical and well placed with regard to the body parts, Sridevi stays with him always and is covered with ornaments. Well, there are no ornaments. Also, the idol doesn’t confirm the form of a meditative image because it doesn’t have Abhaya posture.

All these point to some possibilities –

  1. That the statue is self-manifest
  2. That the statue was sculpted before the Agama Sastras were written making it one of the oldest statues in India
  3. That the sculptor didn’t know the Agama Sastras
  4. The sculptor diverged from the Agama Sastras out of contempt or to give an impression that the statue is self-manifest
  5. That the statue is not of Lord Vishnu altogether and was appropriated later.

Rationally, I will go for arguments two and three, but in a land of continuous religious ideological changes, what is not possible?