Interesting question and I could visualize use-case for the same. Note that S3 is in ideal location for enterprise use-cases while Amazon Drive is alternative of Google drive and is more towards customer focussed a b2c solution... Primary purpose of Amazon Drive is to let photos/documents be in sync across different devices of customer and secondly, auto upload of photos taken.
Having said that, ofcourse u can use S3 to store your images and then you have many sdks in all languages through which your ec2 can interact with s3.
But if you want to use amazon drive; you can refer https://developer.amazon.com/public/apis/experience/cloud-drive/content/restful-api
Note that as S3 is focussed towards enterprise; you have loads of options and easy apis as compared to with amazon drive.. You can also try uploading images to Google drive.. they have much better apis and your ec2 can talk to google drive apis.