Not the above poster but: it is _so_ much faster to figure out what somebody is doing wrong like this.
My first preference is a screenshare or video conference, so I can see what they see. Second is a phone call. Third is live chat like IRC or Slack and emails are a distant last place.
The same reason why sometimes meetings are actually important and faster to come to a decisions than email or chat. When you have all the stakeholders in front of each other, either physically or virtually, information is disseminated and decisions come together much quicker.