Actively wait for seen to appear.
For some people knowing at what time a person has seen their message is a reply in itself. With that information they can calculate how much time people need to reply to their messages or they can assume all sorts of things if they don’t get a reply.
When chatting online it is a meta information that is sometimes equivalent to blushing or uncomfortable silence in the offline life.
“When I am seenwaiting I cannot focus on anything else”
“I seenwaited for an hour, but once she saw my message the agony became even worse”
“Although I did my regular day activities, I was subconsciously seenwaiting the whole day”