It is not uncommon for me to see sample slides sent by participants for my customized workshops that contain complex images. These images, which can be pictures or diagrams, usually come from a drawing program or other source. If you show the entire image on the screen and use a laser pointer to try to guide the audience to different sections of the image, it can be distracting and not very effective.
A better approach is to break the image into pieces and build the entire image by showing each piece one at a time. This way you can give context and additional detail about each piece without the rest of the image distracting the audience.
You can do all of this within PowerPoint using the image cropping tool and the animation feature. The easiest way for me to show you is by demonstrating it in the video below.
If you want the audience to understand your explanation of a complex image (picture or diagram) and to allow the slide to print or PDF correctly, break it apart using the steps in the video above.