There are plenty of old book covers with characters posing that no one complained about.
Personally, I think people just prefer the way oil paintings look.
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The medium does go a long way in making this world feel more authentic for me, that's for sure, but also think there's more to it than that.
First, the look on the warrior here. Her expression tells me she's "sizing me up". This tells me we haven't met before and allows me to imagine myself as a friend or foe. The unicorn, seems more on the distrusting side. I immediately start to wonder why, especially since there's a pain to it.
Also, she's interesting! Why is she out here? How did she tame a unicorn and train it for battle? Does she have anything to do with the buildings in the foreground? What's in the sack on her side? Is it worth fighting her for (evil PC)?
And what about the Realms? I get a sense it's magical, contains interesting NPCs, has fantastical areas to explore, and is dangerous.
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Looking at the new picture, I see an elvish like forest town? Cozy, I guess...
Then a group of adventurers that seem to have no ties to the background town or each other getting ready to fight...something? Honestly, my first thought would be it's an illusion.
Second picture is better; it at least looks dangerous. I'm still not really sure what I'm looking at though. Evil elf casting something while I'm on the ground. What's everything else though? Just looks like a collage of random monsters. Nothing seems to even notice the elf or me...?