Cropping/resizing is also affected by dimensions. If the images have the same dimensions then the behavior should be exactly the same. From the look of it, it seems that the two images below are bigger than that first image which is why I think they are being cropped in a different way.
I am assuming you have used an add_image_size() for your custom thumbnail size. Now if it is possible to have similar sized artworks before uploading you can probably fix this issue. Sometimes proportions might not be the same since they look like logos. In that case you will have to ensure that the image doesn’t take up 100% of it’s container.