Requested feature overview description.
To add a viewport tag such as this one the to the "mobile" pages:
<meta name="viewport" content="width=device-width">
Why would it be useful?
Mobile web browsers, such as the one on the iPhone, read the viewport tag to determine if a web page is optimized for use on devices with small screens. The mobile pages are optimized for use on small screens, but they do not have a viewport tag, so the browser displays them in a large viewport, forcing the user to zoom in. This is not a good user experience. The meta tag will make the viewport as large as the device's screen, which makes them a lot more usable.
What part(s) of the site page(s) are affected?
The <head> tags of:
/post/m
/post/p/