How to View Prototypes in Sketch Cloud
When you open a document in Sketch Cloud, you’ll see any Prototypes it contains in a section at the top of the document overview. Click on a Prototype’s thumbnail to open and preview it in your browser.
Like the Preview window in the Mac app, clicking anywhere on the screen will highlight any Hotspots or Links. To go back a step to the previous Artboard, click the back button in your browser.
If you’ve enabled comments on your document, anyone viewing your Prototype can choose View Artboard at the bottom of the window to leave the Prototype and enter a static view of that Artboard. From there, they can leave comments in the sidebar. To close the Prototype and return to the document overview, choose Close.