Dropping of the lower jaw
The lower jaw of the other person for whom the surprise is arranged for might drop.
If the surprise is big enough, the other person might raise their eyebrows and even touch them. (See Why do people touch their eyebrows while speaking?)
Jumping forward in a chair
The person might jump ahead in a chair while they are being pleased with a marvellous surprise.
The eyes might open
The person will widen their eyes according to the surprise they have got. The bigger the suspire is, the widen the eyes they might open.
Lips move slightly upwards
The edges of their lips may move upwards as soon as they get the surprise.
Raised upper lids
The upper lids of the person might be raised for the surprise they have been gratified with.
The person might stay still for seconds
It may also happen that a person will not be able to believe that the surprise is meant for them, due to which they are astonished and left speechless. This makes them stand still for a moment and do not do any actions for a few seconds. (See the body language of anxiety)
What is the body language of surprise?
What happens to your body when you are surprised? What is the body language of surprise?