How does "Restricted" prevent user error or make it more secure?
The Set Restriction Level option is for applications running in the containment. You have pre-containment alerts to take action on, i.e., unknown applications or digitally signed applications not whitelisted by Comodo.
Looking at her video, she suggests hitting "Run in Containment" on the presented alerts. (The alerts are the same for safe applications.)
If the idea or goal is to run Comodo-approved applications only, then "Block" is the better approach to making Comodo easier or more secure. Isn't it?