Susan is being more rebellious and wants to not be treated like a child. I feel really sorry for the people in the Sensorite costumes. Also, are the Mon Calamari inspired by these aliens? I’m also noticing that there is trend in the serials so far to have funky doors to differentiate one culture from another — no doors are normal door-shaped openings so far: the Daleks had weird triangle-shaped doors that recede into the wall, there’ve been circular doors that recede, and the Sensorites have strange semi-circular doors that swing out.
The Doctor is surprised that Susan can read the Sensorites’ minds. And the serial quickly becomes a story about the internal politics of the society being visited… I suppose throughout the series we’ll see quite a bit of this “palace intrigue” genre.
Susan gets to reminisce and describe Gallifrey. Like Earth, burnt orange sky at night; silver leaves on trees. I wonder how this compares to future descriptions of the planet. It appears that Susan also wants to settle down somewhere — she will, of course, in the next season.