GitKraken: "This repository requires LFS but you do not have LFS installed"

For a repository on GitHub, GitKraken shows:

This repository requires LFS but you do not have LFS installed. Modifying files that are tracked by LFS could potentially harm your repository. Please visit our support site for info on installing LFS.

Button: Support Site

However, their support site does not mention "Large File Storage". And the largest file is about 4 MB. How can modifying "large" files harm the repository - potentially corrupted binary data?

And what steps are necessary to meet the requirements here?

However, their support site does not mention "Large File Storage".

It does, on the Git LFS Requirements page.

How can modifying "large" files harm the repository...?

Git stores each copy of each file in the repository. If you have a 4 MB file, that's no big deal. If you have 1000 revisions of a 4 MB file, that's 4000 MB that is stored locally and transferred every time you clone.

Git LFS works by adding a second object storage area for large files, they will only be transferred when you need to check them out. In the actual Git repository, a small "pointer file" with the information on where to retrieve the binaries is stored. So your repository stays small, but you can get the large binaries on demand.

If you try to work with this repository without installing LFS you will (first) not be able to see the actual binary contents, just the pointer file. You will (second) check binaries into the actual repository, instead of the LFS space, every time you try to add content. It will not be "corrupt", but it will certainly not be what the originators of the repository intended.

This should be as simple as following GitKraken's instructions to install Git LFS.