A new experience for document libraries is coming to SharePoint online and is being rolled out to first release customers. The new experience has some really cool options which I have listed in this blog
The new UI for document libraries is clean without ribbons.
Clicking the information icon at the top right displays the information panel which list the recent activities that happened on the document library.
The information panel for a selected document displays the preview of the document, the document properties, recent activities and Sharing information.
Columns can be easily added or removed to the current view by clicking the ellipses at the right and selecting the columns required for the view
Documents can now be arranged in grid view which shows a smart preview of documents.
Documents can now be pinned so that they are always displayed above the document list.