Uw mapping and textures

Hi guys, I am new at blender and i have faced a small problem with my project. Well i have used an image texture to put an image on my bean bag/chair and then i unwrap it to adjust it. And everything seemed okay till I made a layout of the chair.Image shrank to the center. I understood that it occurred because the shape of a mesh changed. Maybe you can suggest me a solution or give me some advice?

here is one more photo

Did you mean it expanded, not shrank?
There are two ways. Either you add mapping node in material, or manually scale/translate UV map.

After I made a layout of a chair that one part moved to the center of a chair. I thought i happened because uw map changed its shape.