I have the same thing, but only for some. I haven’t really bothered to notice if it’s due to where the image is posted or hosted, or if it’s the image format. But it seems to be something Thunder derps over for those posts.

Yeah, I have the same problem at my end. Not all images, but most of them. Its a Thunder issue because when using other clients all the images are full height.

Try not to use Lemmy as an issue tracker. If you are encountering an issue, it’s best to create a bug report on Github.