How is "Low Activity" defined in Upwork for refunding an hourly contract customer?

Low activity is defined as a segment of time where 50% or more of the screenshots show activity levels below 5.
When 50% or more of the hour block is low activity, the entire hour of payment is deducted.

The message you will receive:

As such, we have reviewed your Work Diary and will be reversing hours logged that did not meet the criteria for Upwork’s Hourly Protection policy.

My question about "Low Activity" in the official Upwork Community: