Docker containers share host os kernel - can't be used to run a different os.

Your options:

• Run windows in a VM. You assign some of your PC resources (ram, CPU cores, storage) to vm. That windows VM is going to be within 1-2% of a PC with the specs matching resources assigned to VM. You won't get GPU acceleration unless you pass the entire GPU to VM, but it doesn't matter for Lightroom. Will run perfectly.
• Run Lightroom with Wine. It runs as just another Linux program via a translation layer. It will get access to all resources your PC has and it won't waste resources running entire 2nd os in a VM, but there is a performance impact of the translation layer. Performance impact varies depending on specific piece of software and sometimes it even runs faster.

Edit: it turns out it does like GPU acceleration, so performance impact without GPU passthrough will be noticeable at least when opening images. Running it on wine is possible, but a pain - it requires manual workarounds and it doesn't run perfectly even with them.

We're all running high performance games through the same thing all the time now. Benchmarks best Windows in most cases.

You'll be more than fine.

How do you run Windows in a docker container. Isn't the point of docker containers that they share the kernel of the host system?

The Adobe installer doesn’t run on Wine; someone got a recent version of Photoshop running once, but it’s a pirated version and it’s super buggy.

You can’t use Windows as a Docker container. Docker containers are not running full operating systems; they just run software on top of the current kernel but isolated from the main userspace, making it look to programs inside the container as if it’s a separate system. Anything that claims to be a “Windows Docker container” is just running a VM in a Docker container, which falls into the same pitfalls.