its more that the Icons are to Clean if you know wath i mean?
You could ask your artist to add some more detail to them in an paint prg so they fit better with the background.
Its to clear right now that they are low detailed 3d models.
I used to use a art prg for fun a whole lot af years ago called poser that gave these results.
It can easially be fixed with a simple art prg by making layers of detail over them.
You now like skin tone or face shadows.
But if its a theme with Clean art so should you not change a thing
Let the artist work and see how the end result are instead as alot change during the process of development.
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