I have heard that the arrangement of dolls and clay figurines in 3,5,7,9 steps is said to symbolize the evolution of life from being gods to humans.
Generally the order with which they arrange the dolls would be that the creators are arranged in the top steps / tiers followed by Rishis, Saadhus and the last step(s) would typically consist depicting the social life behavior ( Chettiyaars, Army man, Wedding, cricket etc). While there are many reasons stated for the significance of golu, I have a feeling it is also a thank-giving way for the potterers.
Generally visitors come to every house in the evenings and adore the arrangements, discuss many things. It is also a way to mingle with other members in the host family. Spicy lentils is offered as prasadam and distributed to the visitors.
When I say mingling with members - a most wanted thing in the apartment these days as we do not know who is our neighbor. This gives a way to shed differences and socialize well.
Many festivals have taken a convenience. Some celebrate it for 9 days while some keep for 3 days. It is also considered to be good if you give vethelai paakku ( betel leaves nuts) to people who visit home... A reminiscenting memory when I used to be child and sing songs to get sundal(only if you sing, you get mind you). I vividly remember all my inviting occasions where I went to houses and invited them.
The next day / within 2 days based on convenience, everyone visited our house to see the dolls and sang songs. Only of late, the reciprocation of visiting homes (also heard the same from another friend) has come down as priorities differ for individuals. During one of my visits to houses, I heard from an elder person that during this time, it is supposed to be punniyam / sacred when you GIVE vethalai paakku and RECEIVE vethalai paakku...
Signing off
Hema