Error: “mime_content_type(): Can only process string or stream arguments”?

Question

Laravel

I want to make the distribution of files when uploading to different collections (pictures to pictures, videos to videos, etc.). Here is the method itself, with a single comparison, as an example:

public function uploadFile(Request $request)
    {
        if($request -> hasFile('file')) {
            $task = Task::find(1);
            if( mime_content_type($request) == 'image/png') {
                $task->addMedia($request->file('file'))->toMediaCollection('images');
            }
        }
    }

gives error mime_content_type(): Can only process string or stream arguments