Apple's (NASDAQ:AAPL) recent Worldwide Developers Conference was a bit of a mixed bag for Facebook (NASDAQ:FB).

Facebook has been building a set of features that make it a far more relevant platform on top of a mobile operating system (i.e., deep linking, where it kind of sets the definition for a sort of "page rank" for apps). But in some ways, Apple undercut Facebook's deeper ambitions by introducing better app discovery and extensions between apps.

Extensions work pretty well for Facebook, as the company can integrate far better into a lot of third-party apps. Yet Apple also copied a number of features from WhatsApp (and other messaging apps) into iMessage to improve that system. All things considered, the conference was hit and miss for Facebook. That situation should play out into the future as Facebook looks to become even more relevant on top the mobile operating system, while Apple borrows its best ideas to build directly into iOS. 

In the video below, The Motley Fool's Alison Southwick talks to Fool tech analyst Eric Bleeker about Apple and Facebook's relationship as frenemies.