If I manually chose to select the winner, where do I do that?

Step 1: Once you receive an email that the test has completed, select the broadcast title. 

Step 2: Scroll to the bottom of the overview. Each message version will display an icon next to its metric value, indicating its status and statistical results upon hover. The winning version is marked with a trophy icon, the best candidate with a ribbon icon, and losing or undetermined versions with a bar chart icon. Below are examples from three separate broadcast tests

Winning (trophy icon):

Best candidate (ribbon icon):

Losing or undetermined (bar chart icon):

If statistical significance was enabled, the p-value of the losing or undetermined message versions will be in the popover:

Step 3: Select the winner (what happens after that)

Once a winning version has been selected, either by the user or automatically if that was the winner selection method chosen, the usual metrics cards and graphs will be displayed, with the A/B Tests section now at the bottom. The chosen version will be clearly indicated by green star icons surrounding its metric value.