There is a photo on the page that shows the horizon from a landed position, that’s the one he’s referring to.
It links to, and is displayed, here; with no indication that it’s an artist’s take on what it would look like. It seems to be D. Mitchell’s stitching work from this Venera-13 clear-filter panoramic transmission with added perspective from the color-filter panoramic transmissions.
I don’t think you’ve quite understood ‘/s’. The author was not serious with his post and indicated this fact with ‘/s’. By definition it is sarcasm as that’s what the author defined it as.