The inhabitants of a village are enjoying themselves on a frozen river. In the foreground under a high tree a bird trap has been set up. It’s an old door propped up on a stick; if you pull the string attached to the stick the trap will slam shut. This motif (coupled with the hole in the ice which the skaters seem oblivious of) has often been interpreted as an allegory: the trap will soon kill the birds, the ice can give way under the weight of the people and the hole in the ice is a danger to the heedless skater. The painting therefore alludes to the precariousness of existence.
It is also possible that Bruegel simply wanted to paint an ordinary village scene, and tackle the challenge of representing snow in paint. Writing in The Guardian, Jonathan Jones made the point that in 1565 there was a particular reason why this would be at the forefront of a painter’s thoughts:
Bruegel invented the snow scene, a unique achievement. All the other genres of painting – still life, portraiture, battles and histories, landscape – originate in antiquity. Depictions of snow originate with one man, and one terrible winter.The year 1565 saw the coldest winter anyone could remember. The world turned white, birds froze, fruit trees died, the old and young faded away. It was a shock – and a foreboding. This seemed to be more than just a cold winter. The climate was perceptibly changing, and that is what Bruegel’s snow scenes eerily record. All of them – from Hunters in the Snow painted in 1565, to Census in Bethlehem in 1566, to The Adoration of the Magi in 1567 – were made in response to that year and what it presaged.
The climate was changing dramatically and dangerously, although in the opposite direction from today’s impending crisis. The world was getting colder. Temperatures dropped globally in the Renaissance, so severely that climatologists call the era from 1400 to 1850 the Little Ice Age. The winter of 1565 was one of the first when everyone could see something had changed. But what was to be done?This was a pre-industrial society that had only the most limited control over its environment. The Little Ice Age was a naturally caused phenomenon, and humanity – puny then in the face of nature – could only try to adapt. Bruegel’s paintings are not just prophecies. They are recipes of adaptation, illustrating new ways to live with the cold: how to inhabit it, even enjoy it. Ice and snow turn the world upside-down. In Bruegel’s paintings, the very chill that threatens life provokes vitality. People don’t just shiver in the snow. In his Census at Bethlehem, while adults huddle miserably, children skate and sledge on the ice. … Bruegel captured humanity’s double relationship with winter: we fear it and we love it. Surviving winter is part of what makes us human. For … Bruegel, whiteness is wondrous, frightening – and the world would be a poorer place without it.
[https://gerryco23.wordpress.com/2013/07/29/in-pursuit-of-bruegel-in-brussels-and-antwerp/]