They are part of a large group of aunts, uncles, and even other grandparents. You will almost certainly find cultural and value differences with the other aunts, uncles, and grandparents, to say nothing of the other parent. Sometimes those differences are small. But there can certainly be great variations in how children live, especially when different cultures and values are combined. But bear in mind if children have lots of people who love them and care about them, it doesn't matter if there are cultural or value variations in how these people live.
Different families have different ways of celebrating holidays.
Different families have different cultures and even different religions. Even the dining habits of different families may vary. Actually diversity is healthy. Let's take everyday dinners. My daughter's in-laws are quite formal.