What is Ammavari Unjala Seva
Ammavari Unjala Seva is the swing service of the Goddess; the temple's own list renders the name as "the Goddess's swing service". In a swing service, the festival image ( utsava murti ) of the deity is seated on a decorated swing and gently swung, while lamps are lit around it.
At Sri Lakshmi Narasimha Swamy Temple, Yadagirigutta, the temple's poster lists Ammavari Unjala Seva, the Goddess's swing service, among its sevas.

A festival of the swing
Swinging the deity is an old Vaishnava custom. In Sanskrit a swing is dola, and a swing festival is dolotsava. In the north, Krishna and Radha are carried out in a swinging palanquin at Holi, and the Garga Samhita, a Vaishnava text, speaks of Krishna's swing festival. In the south, the swing service is called unjal seva; at Tirumala, for example, it is held in the temple's hall of mirrors.
What devotees seek
The swing service is an offering of love. Devotees describe it as pleasing the deity the way parents delight a beloved child: by rocking her gently, with lamps and devotion. It is traditionally offered seeking happiness and peace in the home.
Because it is offered to the Goddess, families also choose it in honour of the women of the family: a mother, a wife, a daughter.
What happens
In outline: the festival image of the Goddess is brought to a decorated swing and seated on it. Lamps are lit, and the swing is set gently in motion.
Which form of the Goddess receives the seva at Yadagirigutta, on which days, and what is sung or recited during it could not be confirmed from an official source.
What you receive
When you book through VedaJyoti, you receive a recorded video of the seva.