Dim Sum

This is not really about dim sum, actually.   In the first photo, a group of people is having dim sum, obviously.  A common scene in Hong Kong. 

In the second photo, two groups of people are sharing one table.  Most of us do not prefer it.  But in crowded restaurants, we may not have a choice.

In the third photo, how many different groups are there?  

How about this fourth one?