The data visualization is misleading because the sum of the values for the categories does not add up to 100%, which is a fundamental requirement for pie charts. Pie charts are intended to represent parts of a whole, and the total percentage should always be 100%. In this case, the sum of the values is 100% (40 + 25 + 20 + 15 = 100), so the data itself is not misleading. However, if the data had not summed to 100%, that would be misleading. If there are other reasons for it being labeled as misleading that are not visible in the provided data, they would need to be clarified.