Question: Who is the eerie little girl in the red dress that Sam sees in his TV?
Answer: A 'test card', also known as a 'test pattern' in North America, is a television test signal, typically broadcast at times when no programs are being broadcast. These were used to calibrate the TV signal. The girl in the red dress featured in the most famous UK test card was Carol Hersee, broadcast from 1967 onwards, holding a clown doll.