It appears this is a new behavior of mobile Safari. This is auto expanded. So, iframe definition for width and height will be ignored as it sees fit.

Workarounds for that includes the ability to encapsulate the iframe definitions into divs and move the width and height settings in there as well. But, this implies to adjust your code to take consideration of that, especially if you have javascript that calculates the width and height of the required locations based on the window dimensions.