This example will be to look at impact over 1 day.
Go to trend view, click on the day you want to investigate, from the interval drop down, choose 1 day (that will squish *technical term* the waits into 1 vertical bar), click on that bar.
Now go to the machine tab and choose server B (from server A, that will be the client).
Review the SQL statements originating from SSRS and all other metadata (other dimensions or tabs).