I have a few SharePoint 2013 sites hosted on premise, and one Office365 site that is also SharePoint 2013. I know Office365 has changed the look and feel of the All Site Content page. Is this just a change for SharePoint 2013 for Office365, or is my Office365 site now a SharePoint 2016 site? Is this look and feel for All Site Content going to be available for on premise 2013 sites, or do I have to upgrade to SharePoint 2016 to see this new look and feel?
You will have move to SharePoint 2016 and upgrade to the latest patch, but it'll be a while before you get the new look and feel (Modern Library Experience) in SP 2016. Recently SharePoint 2016 feature pack was announced and will contain:
- Logging of administrative actions performed in Central Administration and with Windows PowerShell.
- Enhancements to MinRole to support small environments.
- A new OneDrive for Business user experience.
- Custom tiles in the SharePoint app launcher.
- Unified auditing across site collections on-premises and in Office 365.
- Unified taxonomy across on-premises and Office 365.
- OneDrive API 2.0.
Hopefully future feature packs will contain the new modern library experience and the new publishing page which is available in developer tenant when you use a workbench.aspx from the SharePoint Framework (SPFx) team.