Why write this lua snippet in .nix file, instead .lua file?

# Why write this lua snippet in .nix file, instead .lua file?
# Due to .lua file throws lots of syntax error for this lua snippet.
# TODO: [feature: Ability to disable/toggle image inline rendering for buffer #1739](https://github.com/folke/snacks.nvim/issues/1739#issuecomment-3413850508)
/*lua*/''
  image = {
    enabled = true,
    convert = {
      ---@type table<string,snacks.image.args>
      magick = (function() -- start of a local scope
        original = {
          default = { "{src}[0]", "-scale", "1920x1080>" }, -- default for raster images
          vector = { "-density", 192, "{src}[0]" }, -- used by vector images like svg
          -- math = { "-density", 192, "{src}[0]", "-trim" },
          pdf = { "-density", 192, "{src}[0]", "-background", "white", "-alpha", "remove", "-trim" },
        }
        -- if vim background is dark then negate the image color
        for _, opts in pairs(original) do
          if vim.o.background == "dark" then
            table.insert(opts, "-channel")
            table.insert(opts, "RGB")
            table.insert(opts, "-negate")
          end
        end
        return original
      end)(), -- end of a local scope
    },
  },
''
Xieby1's Nix/NixOS Config
