When previewing the post or comment being made, pictures that are in the portrait style aspect ratio do not show up in the preview.
Here's an example:
Landscape
Portrait
Landscape
Result
There's also an issue with uploading pictures. All 3 of the pictures on the above example failed to upload unless I cropped them. Using the crop tool and sizing it to be the original aspect ratio/size does seem to bypass the issues.
All of your pictures loaded and looked fine for me.
And uploading also works fine for me. It's probably an issue with your instance or file format? Are your pictures JPEG, or maybe some other format such as HEIC? (By cropping, it's probably converted to jpeg regardless of what the original format was)