A new video of an iPhone claimed to run iOS 14 shows off a new grid-style multitasking view similar to the one running on iPadOS. Ben Geskin, the tipster behind this video, claims that this multitasking view is one of four options that will be available on iOS 14.
https://www.notebookcheck.net/Cards-to-grid-iOS-14-will-bring-grid-style-multitask-view-to-iPhone.454558.0.html