Sorry if this has been done to death! I can't find the answer from googling.
I always thought that the last seen time stamp showed the last time that a person had the WhatsApp screen open on their device, i.e. when they last looked at it /read a message. But I've noticed from seeing someone online that their timestamp is from the last time they sent a message, not the last time they looked. Has it always been that way?
Basically, I received a message, saw they were online for a while after they'd sent it (more than a minute) but later their timestamp was the time of the last message sent to me.
Does it make a difference if it's from a computer rather than a phone?