UIView animateWithDuration is too fast

Try it :

override func viewDidAppear(_ animated: Bool) {
    //You should not edit directly the frame here, or the change will be committed ASAP. Frame does not act like constraints.
    // create the new frame
    var newFrame = self.shapeLayer.frame
    newFrame.size.height += 400.0

    UIView.animate(withDuration: 5.0, delay: 3.0, options: .curveEaseOut, animations: {
        //assign the new frame in the animation block
        self.shapeLayer.frame = newFrame
    }, completion: { finished in

    })
}

Maybe you should try CABasicAnimation

    let fromValue = view2.layer.bounds.height
    let toValue = view2.layer.bounds.height + 50
    CATransaction.setDisableActions(true) //Not necessary
    view2.layer.bounds.size.height = toValue
    let positionAnimation = CABasicAnimation(keyPath:"bounds.size.height")
    positionAnimation.fromValue = fromValue
    positionAnimation.toValue = toValue
    positionAnimation.duration = 1
    view2.layer.addAnimation(positionAnimation, forKey: "bounds")