"Honeycomb plastic walls." Wikipedia:

The US pavilion was quite spacious and included a fashion show with models walking down a large spiral staircase, an electronic computer that demonstrated a knowledge of history, and a color television studio behind glass. It also served as the concert venue for performance by the Seventh Army Symphony Orchestra under the direction of Edward Lee Alley. It was designed by architect Edward Durell Stone.

It's been replaced by the Trademart.