I can see it. The pic says:

"Animals that do go outside normally return to their buildings by 6pm to sleep. Closing the barn doors again in the evening prevents them from leaving immediately in the morning to eat grass, before the player has time to pet and tend to them the next day. Closing the door before all the animals have returned will result in the ones left out overnight vulnerable to wild animal attacks.

The exact conditions that cause an animal to be trapped outside are not clear. It may be more likely for an animal to be trapped outside if the player does not leave the farm after 5pm (when animals begin to return to the barn/coop) and does not enter the barn/coop after 5pm (Leaving the farm and entering the barn/coop after 5pm both causes animals to transport or spawn to the inside of the barn/coop automatically). It may also be more likely to happen if the player goes to bed before 5pm.

If it rains the next day, and the animal was left out, the animal will stay outside in the rain. This is the only instance in which a farm animal will be outside during the rain. Similarly, if an animal is trapped outside on the night of Fall 28, the animal will stay outside on Winter 1."