Jaffa
Home assessments are not significantly different from those held in the Assessment Provider's offices, our PIP Claim guide has sections on this and the questions you are likely to be asked.
The assessor is a visitor in your home and has no more right to look around than anybody else who comes to see you, although in reality, it would be very unusual for them to ask.
There may be a short and simply examination, range of movement, grip and possibly a short walking test.
Gordon
Nothing on this board constitutes legal advice - always consult a professional about specific problems