Highslide JS - Is there a way to have expanded images share a common center?

Highslide JS - Is there a way to have expanded images share a common center?

I'm using Highslide JS with gallery, using a single thumbnail to launch
the gallery. After expanding the image, when advancing through the
expanded gallery, all of the images appear to be anchored at the bottom,
meaning, when you switch from a landscape (long-side horizontal) image to
a portrait (long-side vertical) image, the bottom edge of the image will
stay in one place, and the remainder of the image will expand upwards.
This doesn't work too badly, except if when you go from a portrait image
to a landscape image, the new image is sitting at the bottom of the
viewport. Is there any way to have all of the images share a common
center, and expand from there, instead of sharing a common bottom edge?
That way they won't be constantly moving up and down in the viewport. If I
want to use a thumbstrip, I can't place it on the top or bottom since it
can/will get covered up by an image at times. All of the expanded images
I'm using are 800x536 or 536x800, depending on orientation.