$ php artisan make:migration create_table_posts --table=posts

    public function up()
    {
        Schema::create('posts', function (Blueprint $table) {
            $table->bigIncrements('id');
            # 以下の行を追加
            $table->string('image');
            $table->timestamps();
        });
    }

$ php artisan migrate

$ php artisan make:model Post

    public function store(Request $request)
    {
        $post = new Post();

        # 画像ファイルのアップロード
        $image = $request->file('image');
        if ( app()->isLocal() || app()->runningUnitTests() ) {
            # 開発環境
            $path = $image->store('public/images');
            $post->image = Storage::url($path);
        }
        else {
            # 本番環境
            $path = Storage::disk('s3')->put('/', $image, 'public');
            $post->image = Storage::disk('s3')->url($path);
        }

        Auth::user()->posts()->save($post);

        return redirect()->route('posts.index');
    }

# 開発環境
$post->image = Storage::url($path);

# 本番環境
$post->image = Storage::disk('s3')->url($path);

$ php artisan storage:link

<img src="{{ $post->image }}" />