Her wedding was talk of the town despite having organized everything in India only... While other celeb couple flew to Italy but nobody talked about their wedding later... Priyanka just took a massive storm in worldwide media... I mean her wedding was like a massive storm for the Western media.
Even a middle class family's wedding in India will have 1000+ guests and since she wanted to keep it intimate with just 200 people she definitely had to throw more reception parties. She's in the biz for 19 years and had to invite media people, her colleagues and extended family for the reception. Hence the multiple celebration!