When you block someone in WhatsApp, how is it displayed to them - briefly?
When you block someone on WhatsApp, they will not be able to see your last seen or online status, and their messages will not be delivered to you.
When you block someone in WhatsApp, how is it displayed to them - in detail?
When you block someone on WhatsApp, the experience for the blocked user is largely discreet and non-intrusive. The primary indication they might receive is that messages sent to you will no longer show a delivery status or read receipt. This means the double check marks (which indicate message delivery) and the blue check marks (indicating the message has been read) will not appear for any of their messages directed towards your number.
Furthermore, if the blocked user tries to view your profile picture, it will no longer be visible to them. Additionally, they won't be able to see your status updates or changes in your "About" section. Any calls made to you will not go through, appearing as failed attempts on their end.
It is important to note that the blocked user will still see you in their contact list and can even send messages to your number. However, those messages will remain undelivered and unseen by you unless you decide to unblock them. WhatsApp does not send any explicit notification or alert to inform the blocked user about the block, thus maintaining a level of privacy for both parties involved.
In summary, while blocking someone on WhatsApp does restrict their ability to interact with you and see updates from your account, it is done subtly without directly informing them that they have been blocked.