Except that Seafile (and Owncloud) takes a while to setup, is not easy to setup, and is over-kill for sharing a file or folder publicly. There’s no need to run an entire LAMP server stack just to share files, nginx can handle this for you faster and with less system resources.
Just setup a folder with Syncthing, use nginx Server Blocks to expose that folder publically and you’re done. nginx has autoindex to display files in a folder, or you can install fancyindex for custom theming of your folder display.
So, Syncthing for syncing, nginx for serving. Simple, and much more efficient.
If you need a tutorial on how to set this up, PM me and I can help.