Rear left: (there is minor impact damage on this wheel arch, but that doesn't make up the difference)

Rear right:

And I'm guessing on low the rear is generally lower than the front?
Front left:

Front right:

Is this something to be worried about? I have sometimes felt like the left has been a bit lower than the right, but haven done any kind of measurement until now. Is it just something that needs adjusting or is it likely something needs replacing?