What gets me is any illustration that works like a bit like a map. If you can see a path through the landscape and can imagine yourself stepping into the picture and moving through it and visiting the distant locations that’s perfect. This illustration by Ma-ko https://twitter.com/blurring_my_day/status/1082627757530464261 does it, or like this one by Conner Fawcett https://twitter.com/thebadbucket/status/1087113016347320320 . I think the appeal for me is that the art is showing you a setting, and maybe some information about the world and the people in it, but there’s all this space for your character to explore.
What things do you see in an illustration and think I need to play this game right now?