What does 'Icier' mean? Question about a review of Elementary in the Washington Post [closed]

Solution 1:

Describing a person as "icy" states that they are unfriendly, cold, emotionless:

a. Unfriendly or hostile: an icy stare. b. Showing no emotion: icy detachment.

From the Free Dictionary

Thus, describing someone as playing a far icier version of the character implies that the portrayal is colder, unfriendlier or less emotional than any other portrayal the reviewer is familiar with.