That depends on what you prefer. As a simple solution you can use a service layer with suitable naming convention (Image/Picture/Photo/...) like:
$image = $this->imageService->upload($request);
which you can then reuse for downloading as well you like it that way:
$image = $this->imageService->download($videoId);
Or you can split those two into separate classes (ImageUploadService, ImageDownloadService).
Anyway, you can do your magic inside that class which will keep your controller slim. Feel free to fire various events and listen for them where necessary (e.g. ImageWasUploaded => email notifier , ImageWasConverted => user can download new file, ...).
PS: please remember, that I am talking about service classes ( = classes with specialized functionality based on your needs) and not about service providers ( = classes you mostly use to bind or prepare various stuff)