thumb for portrait picture is landscape (instead of portrait), bottom & top clipped

[doodhout]

Thumbnails are always in landscape orientation, even for pictures in portrait orientation. In that case, the top and bottom of the picture is clipped in the thumbnail, so when I view a portrait of someone, the thumb only displays the stomach or neck because of the clipping.

Is this by design, a bug, or maybe a malconfiguration on my end?

Thank you.