The original "Mane Six" in that they were, at one time, the ONLY 6. The original My Little Ponies in a photo taken with the ultimate of 80s cameras... The pink and grey Polaroid "Cool Cam".
The hairstyles are all actually based on people or characters from that time period, mostly from the Facts of Life. Butterscotch's hair is Cyndi Lauper's from the "She's so Unusual" cover, toned down a bit.