Asuka’s attitude connects a dot in Taran’s mind. Until now he thought she was about his age, but the way she addressed Fenna was military grade teen behavior. She said FYI out loud. But he notices Fenna actively working to keep calm despite the dripping contempt and tries to play nice as well.
Taran contemplates the beanbag. It’s super generous for a beanbag chair, and the fur sure is a choice, especially outside. It isn’t crusty or faded or anything. Has it been here long? Has the station been here that long? There are no apparent trails worn in the grass to indicate construction or maintenance. Well, they are inside the door still. On the train. Is it a holodeck situation? Taran noncommittally pulls an edge of the beanbag up with his foot. Seems real enough. ‘Real’ doesn’t seem to be a problem for the train.
As for Asuka’s verbal banner in the sand laying claim to Terra Nullius, graciously brought to the floor of Taran’s personal court to be ratified and proclaimed to the citizenry; by virtue of being the Third Guy In The Situation, he renders judgement:

“It looks like a perfectly good beanbag chair. If you need to get off your feet, go for it.”
…Okay, he can’t resist being a little smarmy. Sorry Fenna. He pauses for just a second to see if Asuka takes the bait, but completes the thought either way.

“Fenna’s right that it’s weird though. Do you think it’s been here long enough for there to be spiders up in it?”