There are several different things in this episode than in the rest of the series..
1st Ann has Black hair not Red
2nd Gidget's front room, the stairs go to the left instead of the right and the front door is in a different place
3rd Gidget's bed is a double not 2 twin beds
4th The outside of Gidget's house is Major Nelson's house on I Dream of Jeannie..But, later its the house from Leave It to Beaver.