What defines cultural appropriation

Some of the chapters in his book, Hooper tells BBC Culture, are about "the tree itself and what it stands for, as a metaphor for values we hold dear. Robert the Bruce used a 2,000-year-old yew tree, growing through the rocks on the shore of Loch Lomond, as a symbol of endurance as he tried to raise the spirits of his retreating army in 1306. Just 200 men crossed the loch, in a boat that could only hold three men at a time, and as they gathered on the far side by the tree, he compared its ability to survive against the odds with their own. When Robert the Bruce finally won independence for Scotland after defeating the English at Bannockburn in 1314, many of his men wore sprigs of yew on their uniforms."