Select the images to be converted to SmartArt. To select multiple images, click on the first one, then hold down the Ctrl key while clicking the other images.
Go to the Format tab > Picture Tools > Format > Picture layout
In the gallery, click the layout for the SmartArt graphic.
The gallery offers SmartArt graphics layouts which are the most appropriate for your images.
When you have selected a layout for a SmartArt graphic, the images are automatically arranged according to the layout chosen. You can then add text to your SmartArt graphic and customize it by changing the color or Style.