This is probably a good time to address naming inconsistencies. I'm not sure what would be best here. In the `collectionViewFlowLayout` the opportunity to perform an action within the animation block is called in the 'finalize' delegate (if you look at the `MBContactCollectionViewFlowLayout` class, I'm using `finalizeCollectionViewUpdates` to handle animating size changes). Maybe something like `finalizeContactPickerSizeUpdatesForContactPicker:(MBContactPicker*)contactPicker from:(CGSize)oldSize to:(CGSize)newSize`? It's super verbose, but it does match the style they provide for delegates acting on animated changes.