В новом UICollectionView я не вижу, как добавить тень в UICollectionViewCell. Как бы я это сделал. Добавлю другое представление?
    [self.collectionView cellForItemAtIndexPath:[self.collectionView indexPathForItemAtPoint:[recognizer locationInView:[self view]]]].layer.shadowPath = [UIBezierPath bezierPathWithRect:rect].CGPath;
    [self.collectionView cellForItemAtIndexPath:[self.collectionView indexPathForItemAtPoint:[recognizer locationInView:[self view]]]].layer.shadowColor = [UIColor yellowColor].CGColor;
    [self.collectionView cellForItemAtIndexPath:[self.collectionView indexPathForItemAtPoint:[recognizer locationInView:[self view]]]].layer.shadowRadius = .5;
    [self.collectionView cellForItemAtIndexPath:[self.collectionView indexPathForItemAtPoint:[recognizer locationInView:[self view]]]].layer.shadowOpacity = .1;
 