That was a ST:TNG episode!
I think the problem is if you place the image as part of the post when it's hosted elsewhere, without uploading it to the MR server and it's over that size limit. If you upload the images to MR within the post, MR resizes them but then lets you click them up to full size, and the 600x600 pixel limitation seems no longer a concern.
But I did see the image before it was deleted and it definitely had a yellowish cast to the top part fading down to bluish/white. Honestly that would drive me crazy.