Horizontal Type of Gallery allows batch uploading and management of image galleries, slideshow and thumbnail style galleries, editing of thumbnails. WordPress Photo Gallery also allows you to select several types of images layout. To switch on the Horizontal Gallery move to Gallery Type section in Main Gallery Settings.
Establishing pictures height in the Horizontal Type of Gallery, your photos width will be automatically transformed accordingly to original size. So this gallery type is the most suitable for photos with landscape view type. You can adjust the same example like this —