The slideshow plugin element is set to 200px tall, and technically the overall element is, but the actual slideshow itself is less than 200px. That’s the thing that has the border drawn around it.
The dotted border is a text element that’s also set to 200px tall and, from the border, you can see that it is actually 200px tall.
Is the slideshow supposed to be some undefined number of pixels shorter than specified? Is this a bug or is it supposed to work that way?