Good day, evening or morning.

I have to pose this question on a very simple shape, a rectangular plane, with just a wee smidgeon of thickness.
So let's begin.

I have been modeling, shaping, and uvng objects in a scene and I came to a "rug", let's just say, and I was looking at the uv from both a camera based and automatic. The original jpg file is oblong, like a rectangle, not square, however, when I look in the UV Editor, the file image is square in the grid as are the uvs.

Now, question, I told you freegin senior moment, do I need to "shape" the uvs to look like the rectangular shape in my scene or? And why did the jpg, that is clearly rectangular in Photoshop, turn square in the UV editor?
I will need to "paint" some of the info in PS, and a few other things, maps etc, so I wanted to make sure this is what I should or shouldn't do.

Thanks!

Forgive this old man's ramblings.