The picture shows a solitary fisherman rowing with only his paddles in the middle of the ocean, looking over the horizon or at another sailboat. The sky is dim and ominous with a surreptitious, encroaching wall of fog approaching, influencing an uncertainty and unpredictability; the sea isn't calm but disturbed with constant revolvement of high and low tides.
The title "The fog warning" may indicate a certain insecurity and aimlessness in life with the intention of seeking a quiet bay to settle before the storm's coming. Or it could convey humanity's deep need for connection in a void.