Samantha, having been through Tommy’s poor me presentations on previous occasions now, during Covid, is requested to call him.
Instead of using her cell phone, she used messenger so as to have a face to face conversation.
Having been through the abuse Tommy attempted to inflict on her before, having analysed it, she knew what to expect.
This is the key feature.
This is not the mother innocently exposing herself to her son’s abuse, this is the mother who was fully aware of the vicious nature of her son and his need to hurt.
She knew he wanted her to call so that he could waste her phone credits. She knew that using messenger would annoy him.
For Tommy, getting people to spend money on him, whether a phone call or a paper card, meant more to him than sentiment.