Masonry gallery, image display issues

When I use a masonry gallery (using all the same size images, by the way), I don’t understand why the thumbnail image doesn’t display it centered? It seems to display the lower part of the image. Then, when I click on the thumbnail and it shows via the lightbox, the image looks normal. Basically, if I want the centered part of the image displayed in the thumbnail (which should be normal/standard to my way of thinking), I have to enlarge the imaged and move the part I want displayed higher, just to have it look centered in the thumbnail image. But then, when it opens in the lightbox, it looks bad because of this modification. I simply can’t use the masonry gallery as a result — which was one of the reasons I liked Enfold in the first place. Is there any way to fix this behavior?

Sorry, no link because I’m developing the site locally.