Maybe the son shares fictional stories that involve characters' facial expressions. For example, he might tell about a character in a book who had a very surprised face when they saw a magical creature. It could also be stories where the description of facial features plays an important role in the plot, like a detective noticing the nervous twitch on a suspect's face.
Well, in the 'big mom is luffy's mom fanfic', they might have crafted a story where Big Mom is Luffy's mom. But it goes against what we know from the official 'One Piece' story. Fanfictions like this can be really interesting as they can rewrite the story in unexpected ways. They might have some interesting plot twists and explanations within the fanfic to justify this relationship, but it's not part of the main 'One Piece' universe.
One possible plot implication could be a change in Luffy's power source. Since Big Mom has such unique and powerful abilities, Luffy might inherit or be related to some of those powers in the fanfic. Maybe his Devil Fruit ability could be related to Big Mom's in some way.
Bonding. It is a great opportunity for mother - son bonding. Through the physical touch and the time spent together during the massage, their relationship can become closer. The son feels cared for and loved, and the mom gets to show her affection in a very direct way. Also, it can be a time for communication. The mom can talk to the son, give advice or just have a friendly chat while massaging, which is beneficial for the son's emotional well - being.
Perhaps it's a custom - made piece of jewelry with his mom's birthstone. He might have saved up money for a long time to buy it. He knows his mom loves jewelry and this would be a very special and personal gift. It shows that he has put a lot of thought into choosing something that she will cherish.
As of now, in the manga, the identity of Luffy's mom remains unknown. There have been many theories and speculations among fans, but no official confirmation.
I'm not sure specifically which 'Michael gives mom' story you are referring to. It could be about a gift that Michael gives to his mom, like a present on a special occasion such as her birthday or Mother's Day. Maybe it's a handmade item or something he bought with his own money to show his love and appreciation.
One day, the son had been playing outside all day long. When he came home, he was really tired. His mom noticed how exhausted he was. So, she asked him to lie down on the couch. She gently started to massage his legs. She used just the right amount of pressure, kneading his muscles. As she massaged, she told him stories about when she was a kid and how she used to play in the fields. The son felt so relaxed and happy, and he started to doze off a little while listening to his mom's stories.