The problem is that you're trying to change the view's frame with Auto Layout on. You can't do that. The Auto Layout system will overwrite your changes. Try turning off Auto Layout in your storyboard and you'll see that it works.
So your options are:
- Don't use Auto Layout
- Use/manipulate constraints instead of frames.
For (2) you can just go into the storyboard and set up width and height constraints on the container view and it will work. If fixed size isn't the exact behavior you want, you'll need to be more explicit in your requirements.
The default constraints you're getting now are attached to the parent view and aren't getting carried along for the ride when you move the view to a new parent.