It's an nginx-php container which aims to provide a fast and secure foundation for deploying Magento to either development or production. Based on Phusion's BaseImage, it includes at time of writing:
Mozilla's intermediate SSL profile
mandatory cron tasks pre-configured
Most important aspects of an nginx / php webserver are configurable at container start, such as memory limits, file upload sizes, user permissions and mail delivery via SMTP smarthost. Please see parent image documentation for all configuration options.
LetsEncrypt support is planned for near future, and I welcome contributors to the github page, as well as comments or suggestions as to how I could make this container more helpful. I have also considered automatically installing latest Magento if the root directory does not contain Magento.