FANOUT => MAJORITY gate:
With one input line, this arrangement of QCA cells provides for FANOUT of a signal.
However, when there are three input lines, it will instead act as a MAJORITY logic gate.
A majority gate is like a digital voting machine: If the majority of the three input lines are in logic state 1, the output goes to 1. If the majority of the three inputs are in logic state 0, the output goes to 0.