Well I just noticed that this actually is a bug which occurs when no sidebar is set. It’s not supposed to be that cropped, so really great you noticed! And thanks for letting me know.
I’ll add a fix for this in the next update. In the meantime it’s better you change that css to the below, or it will look bad when you have more than one post.
@media (min-width: 768px) {
article .article-body .article-image-div.article-half-size {
max-height: 1000px;
}
}