Fatal error: Call to a member function guessExtension() on array - Multiple image upload

I am trying to upload multiple images over my laravel rest api.

I am injecting a form validation to my controller that has the rule: 'images' => 'required|array|min:1|max:5'

If it passes it will go into the controller where I have this:

 $files = $request->file('images');

     foreach ($files as $file) {
         // Validate each file
         $rules = ['images' => 'image|mimes:jpg,jpeg,bmp,png,gif|max:9000'];
         $validator = Validator::make(['file'=> $file], $rules);

         if ($validator->fails()) {
           return response()->json(['errors' => $validator->messages()->all()],400);
         }

         $newUser->uploadThumbAndMainImage($request,$userId);
     }

And finally the model function

public function uploadThumbAndMainImage($request,$userId)
    {
      // get basic info
        $s3 = Storage::disk('s3');
        $file = $request->file('images');
        $extension = $request->file('images')->guessExtension();
        $filename = uniqid() . '.' . $extension;
        $mimeType = $request->file('images')->getClientMimeType();
        $fileSize = $request->file('images')->getClientSize();
        $image = Image::make($file);

        // generate the thumb and medium image
        $imageThumb = Image::make($file)->fit(320)->crop(320, 240, 0, 0);
        $imageThumb->encode($extension);

        $imageMedium = Image::make($file)->resize(800, null, function ($constraint) {
            $constraint->aspectRatio();
        });
        $imageMedium->encode($extension);

        $image->encode($extension);

        // upload image to S3
        $s3->put("images/{$userId}/main/" . $filename, (string) $image, 'public');
        $s3->put("images/{$userId}/medium/" . $filename, (string) $imageMedium, 'public');
        $s3->put("images/{$userId}/thumb/" . $filename, (string) $imageThumb, 'public');
    }

But I get the error: Fatal error: Call to a member function guessExtension() on array

And yeah I post my images as "images[]" since I am allowing to upload multiple files at once.