Family unity might also be a theme. Since weddings bring families together, there could be a focus on how different family members come together to celebrate the union of the couple.
Love and commitment could be a major theme. After all, it's a wedding story.
Another possible theme could be new beginnings. The wedding marks the start of a new chapter in the couple's life, and the story could explore all the hopes and dreams associated with this new phase.
One possible theme could be family. Indian culture places a great emphasis on family values, so the story might revolve around family relationships, like loyalty, sacrifice, or family disputes.
One possible theme could be discovery. Since it's about a big box, there's likely something to be found inside, like new opportunities or hidden treasures.
One possible theme could be size. Since it's a big pig, the story might explore how being big affects the pig's life, like it might face difficulties in moving around or might be intimidating to others.
One possible theme could be perseverance. The racers keep going no matter how difficult the race gets.
One possible theme could be perseverance. If the big blocks are obstacles, the characters in the story might need to persevere to get past them.
One possible theme could be love. Maybe the 'big red one' is a symbol of love, like a big red heart - shaped object, and the story is about different forms of love such as romantic love, family love or friendship love.
One possible theme could be good vs. evil. Since it has 'big bad' in the title, there might be a clear distinction between a 'bad' force or character and those who oppose it.
Another theme could be teaching or mentorship. Just as the big sister taught her younger sister to paint. Big sisters can pass on their knowledge and skills to their younger siblings, which is a very positive theme in these kinds of stories.
One possible theme could be deception. If there's a big lie at the heart of the story, then the exploration of how that lie was created and maintained would likely be a key theme.
One possible theme could be transformation. Just as the universe transformed after the Big Bang, the characters in the love story might transform through their relationship.