Jump to minute 1:16 in the video below.
When setting up a concealed review process, organization administrators can choose how to present concealed fields to their reviewers. You have a choice to either let reviewers see that the concealed field exists, yet the response is hidden from them; or you can hide the field completely, so they won't know it exists. To make this choice, go to Projects and select the relevant Project. Click on the Notifications tab and scroll to the checkbox that says Exclude Concealed Fields. Check the box to hide the fields completely.
If you leave this box unchecked, concealed field(s) will still be shown to reviewers, but the submitter response area will show as [Concealed]. Below is an example of what reviewers would see if you choose not to exclude concealed questions: