This answer explains that when used to indicate a place, で means the action is happening at that place while に indicated the verbs causes a change in place. That all makes sense until I run into some sentences where に is used but there seem to be no change of places.
私の掌に灯る誰も知らない線香花火 ー「線香花火」
草の上に地図を広げた 思い出は風の中 ー「夏の贈り物」
I'd fully expected で since 灯る and 広げる was done in that place, just like 部屋の中で灯る or 部屋の中で地図を広げる. Why the に?
私の掌で灯る線香花火 and 私の掌に灯る線香花火 describe the same scene, but the latter has a poetic sound to it. I get an image of the light emitted from the stick firework shining the palm from it. The version with で, in contrast, is more matter-of-fact and has its focus on where it is burning.
The difference between 草の上で地図を広げた and 草の上に地図を広げた is much greater. The former means you spread the map while you were on the grass as で denotes a place within the boundaries of which some action or event happens. The version with に means you spread the map onto the grass. This does involve a change of place as the map is now on the grass as a result of the action.
