These beautiful photographs are wonderful conversation pieces themselves. Consider just what you can see in the pictures. What can you observe about the family, what their lives were like, what they did while they were on vacation in the Summer of 1946 on Cape Cod.
Also, you can talk about the time. These pictures were taken the first summer after the end of WWII. One thing to think about is what this family was doing one year before these pictures were taken.
Talking about summer vacations is another possibility. What kinds of memories do you have about summer vacations? Did you go to the beach, the mountains or stay at home? Did you ever visit Cape Cod? How did you travel? What did you like to do there? How did being in vacation change the dynamic in your family?