The Joker's Provokers (2) - S2-E22
Revealing mistake: When Alfred talks to his twin Egbert, as they face each other, you can plainly see the line dividing the screen so that Alan Napier can play both parts.
An Egg Grows in Gotham (1) - S2-E13
Revealing mistake: A lot of the time, especially in close ups, you can see the line between the bald dome wig and Vincent Price's real skin, as well as the different coloring of skin.
Answer: There were three well-known actors who played Mr. Freeze, each one a different height, weight, and physique. As these were notable guest stars, the costume designers would adapt the costume to best fit each actor who likely would want to avoid comparisons to the other Mr. Freezes, incorporate their preferences, as well as refresh the look, rework whatever didn't work in previous versions, and so on.
raywest ★