Your comment I was replying to said "I don't know where you are reading that Vivaldi is closed source. The source code is right here: https://vivaldi.com/source/". I was responding to that with Vivaldi's statement about how the browser is closed source.
In your original comment you illude to it being neither open or closed source, which is not true either since it is closed source. Maybe you meant source available? I didnt read anywhere saying that.
Source available is closed source by the OSI definition, which is what is widely used and understood. The "closed" in closed source doesnt only refer to source visibility but also the freedoms upheld by open source.