What do "observers" normally do? How close are they normally allowed to be? Can you read a ballot from 6 or 10 ft away? Does that affect the ability of observe

What do "observers" normally do? How close are they normally allowed to be? Can you read a ballot from 6 or 10 ft away? Does that affect the ability of observers to observe whatever it is they are responsible for observing? Does COVID justify relaxing the rules on observation of a vote count?