I completely agree with the Ricci's and Lee Kun's responses. The podium displays the mortal forms of bosses, so if they differ from the original appearance of the boss - we can be sure that the form we can defeat will be presented.
Below is an example of Goshnar's Megalomania, which in its final mortal form resembles the usual Lich:
Recently browsing Instagram, I also came across a screenshot of one of the players, where you can notice Zushuka's podium appearance. Credits go to @meowsiita:
In the screenshot, you can see a podium displaying Zushuka with blue hair, and as you know - this is her mortal form.