added lightbox to image.

Author: stevemunk

articles/azure-maps/power-bi-visual-add-pie-chart-layer.md

@@ -16,7 +16,7 @@ This article describes how to add a pie chart layer to an Azure Maps Power BI vi
 
 A pie chart is a visual representation of data in the form of a circular chart or *pie* where each slice represents an element of the dataset that is shown as a percentage of the whole. A list of numerical variables along with categorical (location) variables are required to represent data in the form of a pie chart.
 
-:::image type="content" source="./media/power-bi-visual/pie-chart-layer.png" alt-text="A Power B I visual showing the pie chart layer.":::
+:::image type="content" source="./media/power-bi-visual/pie-chart-layer.png" alt-text="A Power B I visual showing the pie chart layer." lightbox="./media/power-bi-visual/pie-chart-layer.png":::
 
 > [!NOTE]
 > The data used in this article comes from the [Power BI Sales and Marketing Sample].