What is a family portrait? What are some famous family portraits? How would you take a family portrait now?
I think family portrait reflects the society.
People would generally put on clothes that they think are formal enough to show their wealth and taste and yet at the same time show their affections towards their family members.
Taking the famous royal family as an example, instead of keeping distance and maintain the mysterious feel of the royalties, they start to use new media, especially internet, to portrait themselves as more affectionate towards their people. Therefore, except the formal portrait that they used present to the public, they would also try to show family portrait that represents more relaxed and down to earth life. I guess that is why they include the dog. Also, unlike the second picture, whereas all ladies are wearing a hat and all men are in suits, the first family portrait make you image a normal family life instead of political influence of that family.
Another aspect of family portrait is that it shows the society structures. All the advertisement that use family portrait as a selling point are very aware of that.
As you can see, family portrait in Singapore normally contains parents and at least two children. However, if this advertisement was from China, it would only contain one child.
Those are simply because Singapore government advocate families to have more children, while China government carried out the famous One-Child Policies since beginning of the 90s.