Hello Terry, For me, in the U.S., "to get a better picture" means to "increase the clarity" of something. Think of a person who is trying to investigate video footage from a crime. The investigator has found a video that shows the suspect (the picture) but the image is blurry and hard to see. The investigator has to zoom in and make the image more detailed to see the suspects face clearly. This is a concrete example of "getting a better picture". Keep in mind that "getting a better picture" is not limited to physical video or photos. You can also get a better picture about abstract things like concepts, ideas and feelings! I hope that is useful for you, Terry. If you would like to connect with me though my italki Teacher account, I would be happy to help you reach your English goals faster :)

"A better picture" means to understand something better. If you have a better picture of your problems for example you will know how to solve them. It means knowing a lot of details about an issue. Hope I helped :-)