Thanks mishy can you expand a bit as that hasn't really helped? What is 'internal mind' - do you think that has some relation to a physical body?
Does someone need to have e.g. no breasts to be a man? I can understand that 'external body presentation' might fit this box - but what if you have breasts but internally you are female - what about that internal feeling necessitates being a non-breasted person?
Are sex and gender not really that different? Is gender, broadly speaking, basically the concepts of masculinity and femininity? What have those got to do with bodies - we all know masculinity isn't a necessary nor sufficient condition to be physically male, and vice versa?
All of this seems to be increasingly 'gender conforming' - men are non-breasted people on testosterone, etc. Which suggests the concept of an internal gender unlinked to sexed bodies is false. This is where I don't understand.