Nature Scientific Reports where this is published is so called mega-journal. They accept practically everything that is technically sound, even if it's not scientifically important.
They do two basic and technically sound things in this paper.
1. Detect yes/no answer from EEG-singal when user is looking light that flickers in different frequency depending on the answer.
2. User is able to detect when transcranial magnetic stimulation is used to signal his brain.
It's not the bleeding edge science but neither of these is technically trivial experiments to set from scratch. Surprising amount of work is spend just setting it up and getting everything right, and fixing all errors. Writing technical report detailing of they did would be probably interesting at least for some. It's unfortunate that they feel the need to tie it up into this brain-to-brain gimmick stuff.
They do two basic and technically sound things in this paper.
1. Detect yes/no answer from EEG-singal when user is looking light that flickers in different frequency depending on the answer.
2. User is able to detect when transcranial magnetic stimulation is used to signal his brain.
It's not the bleeding edge science but neither of these is technically trivial experiments to set from scratch. Surprising amount of work is spend just setting it up and getting everything right, and fixing all errors. Writing technical report detailing of they did would be probably interesting at least for some. It's unfortunate that they feel the need to tie it up into this brain-to-brain gimmick stuff.