It is possible to animate picture buttons using the Switch every x Ticks option. Enabling this option will cycle through the contents of a picture button at the specified speed (in ticks). If you enter 5, the thumbnails will change every 5 ticks.
1. In the Design environment, open the Form editor
2. Open the Object Property List for the picture button
3. Locate the Animation section in the Object Property List
4. Enter a value to Switch every X Ticks
5. Open your form in User mode and watch the button change