title: Runtime UI issue caused by "View as: xxx" in storyboard editor
body: <p>My app has a UI bug caused by some unexpected view width in runtime, e.g. it is 375 when it should be 320. But that might not be relevant to the question I’m trying to ask here. That bug was fixed by only changing from <strong>“View as: iPhone 7”</strong> to <strong>“View as: iPhone 4s”</strong> in my main storyboard (see attached screenshots). BTW there is no warnings and errors in the storyboard.</p>
  
  <p>I’m using Xcode 8.3.2 and always test on iPhone SE simulator and iPhone 5s device.</p>
  
  <p>So my question is: should this change of “View as: xxx” in storyboard editor affect the behavior of an app? If I want that this change will never change the behavior of my app, where in the storyboard should I check? Or what storyboard config I missed?</p>
  
  <p><a href="https://i.stack.imgur.com/IieGN.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/IieGN.png" alt="enter image description here"></a></p>
  
  <p><a href="https://i.stack.imgur.com/ChTbT.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ChTbT.png" alt="enter image description here"></a></p>