One of the organizers (the man with the clipboard) tells a female co-worker, "There was a gust of wind and we lost 12 models". In the background, a man is pushing a rail full of clothes.
The joke is that models are so thin that they can be carried off by a gust of wind.
A gust is a sudden strong increase in the amount and speed of wind that is blowing. • A gust of wind blew his hat off.
To lose is an irregular verb: lose - lost - lost