Yeah I wonder why they didn't translate that in the English version?
I mean it's a pretty important piece of info.
Interesting that these two were lovers...
So Gods falling in love and consummating is a thing in this game.
Referring back to the other mythology portrait, the two gods embracing... I wonder who they represent?
Knowing that they used to be lovers does make that kiss all the more interesting. You'd think she would side with him but she destroys him lol
Translations when coupled with localization is a funny thing. I think the lore ended up adjusted from region to region based around perhaps the team's preferences for which lore to include, and that region's tastes when it comes to this kind of thing. Germanic lore is full of tragic romance between deities or god-like beings, Japanese is less so but includes more fine detail when it comes to deities' roles (like Ifrit just giving Fire in English and giving both flame and knowledge in Japanese), while in English it appeals more to a sweeping and simplified view that many hold about classical religions or the dominant Abrahamic faiths.
As to why Shiva didn't side with Ifrit, I think that's fairly straightforward. According to the bestiary entry outside English, Ifrit was driven insane after being infected by the Starscourge. We know he turned against the Astrals as he was labelled "Betrayer", so it's not too difficult to assume they were forced to kill him after he was infected. The form faced by Noctis is Ifrit reborn from the Starscourge, likely as Ardyn's thrall. So I'd see Shiva's actions in this instance as a kindness towards her lover. And while without context the kiss just seemed like a cruel mockery or over-the-top drama for its own sake, with the context it's actually quite a sad farewell.
And... the portrait. If you're talking about the Genesis mural, given that one of them has a fish tail and the other has wings, I think they're just highly humanized portrayals of Leviathan and Bahamut. Within the game's context was painted after Ifrit's fall, so he was probably scrubbed from the records.