The operation method of setting the desktop background as the material package of small red flowers is as follows

2. After dragging the picture material to the desktop, right-click the desktop and select the "Properties" option.

3. In the Properties window, select the Desktop tab, and then click the Change Desktop Element button.

4. In the desktop element window, find and click the background button.

5. In the background window, select the custom desktop option, and then click the Add Picture button.

6. In the Add Picture window, select the required picture material and click OK.

7. After adding the picture material, click the "Return to Default Desktop" button to set the desktop background to the default state.

8. After setting, if you want to set the desktop background as the picture material again, just repeat the above steps.