It is common if you look back through historical photos especially those within the same time period that beauty was represented in models in similar ways. This means that hairstyles and looks that were believed to be beautiful had a certain look to them. For instance, in the 1970s, it was feathered hair that was long. Then you would see similar beautiful people looking similar because their hairstyles and other factors were the same or similar. The same can be said the about today.

Today, beauty is very similar and predictable. This may be why every Instagram model looks the same. They also may be posing in similar positions and so they may look similar just by their poses and appearances.