‘Dyatha’ is also Narayana, and the one who is meditating is also Narayana. It is all Narayana - inside, outside and everywhere. This is seen in all the mantras of the Gods. For example, in Ganapati mantra ‘Artharvashirsha’ - it says, 'Lord Ganapati is present everywhere - behind me, in front of me, beside me, above me, below me, inside me and outside of me'. Similarly, Narayana is present everywhere, before, behind and in front. This was a way to meditate.
In earlier days, they used to keep an Idol or kalash (pot of water), worship it and settle within themselves. In the course of meditation they would start to feel the presence of Ganapati all around, inside, outside, above, below, in front and then this would take one into Samadhi. The main purpose of all this is to go into Samadhi.
Another aspect is that, when we engage with the outside world (through rituals), it creates positive vibrations within us and affects the atmosphere positively. The same results are obtained when yagyas and poojas are performed. Therefore, these are the two aspects - firstly, to be established within oneself and to be in a state of Samadhi, and secondly - to purify vibrations and bring positivity in our behaviour and in the atmosphere.