Specified size suggestion = 200px
Content size suggestion = 150px 
Automatic minimum height = min(150px, 200px)
 fallback size from last bullet point in https://drafts.csswg.org/css-sizing-3/#intrinsic-sizes :
For boxes without a preferred aspect ratio:
* If the available space is definite in the appropriate dimension, use the stretch fit into that size in that dimension.
* Otherwise, if the box has a as its computed minimum size (min-width/min-height) in that dimension, use that size.
* Otherwise, use 300px for the width and/or 150px for the height as needed.
Pass condition: there is a 150x150 green square.