Empty Shelf Syndrome
This picture was originally going to go elsewhere as a warning about relying on supermarkets for supplies.
It was taken just after the 'Beast from the East' hit the UK two weeks ago, and supplies couldn't get through because of the snow. In contrast, our local farmers' market had a plenitude of goods! Thus, the environmental lesson is reinforced, to support local produce.
However, Feng Shui has other insights to offer in addition to the ecological. First, the idea of mostly eating what is in season is a way of encouraging harmony with nature, and with the Five Elements. This is therefore good for your health and for the planet. Eating lettuce in winter, for example, even if local is not recommended - not only is that out of season, but relies on heated greenhouses, and therefore has a heavy carbon footprint.
For shopkeepers, empty shelves are devoid of ch'i and require something in place. If it does happen, and inevitably it will sometimes, the recommendation is to fill the gaps with something positive, whether artistic or informative or both. As the saying goes, if you get lemons, make lemonade, or at least a picture of it!