It means that someone will make a picture (probably using a computer) for you. You tell them what you want, and they will make it for you. Custom - made to order for a specific customer. So, if I have a custom guitar, it was made only for me. Made - the verb Graphic - a piece of visual art, a picture. Here, it probably means that the picture was made using a computer.

The graphics is made to meet custom's requirement.

Custom made graphics can include business cards, wedding invitations etc