It is a traditional way to invite to tango with a single eye contact and head movement.

Cabeceo is initiated by a man. He looks at the woman who usually sits at the table. A woman can bow her head, which means she does not want to dance with a man. However, if he maintains eye contact, this is an indication of an invitation. The man, not taking his eyes off, comes to the woman and accompanies her to the dance floor. Then they both stand on the dance line, counter-clockwise, and the man gives his left hand.