The tweet at the top has the rest of them attached as a screenshot which does make it a bit confusing.
Lake Superior's tweet (the "innermost" one) came first. Tom quote-retweeted it. Lake superior replied to Tom's tweet. Ron took a screenshot of the whole exchange and posted it as his own tweet.
Sometimes it goes backwards. Next they are going to post everything sideways and the dates will be encoded in a base 12 abacus representation of the Vietnamese calendar.
The red numbers show it chronologically. Twitter has replies and quote retweets. This began with the purple quote retweet. To which Lake Superior responded. Then in green I think this is a quote retweet (or more likely a screenshot) of the exchange. (I don't think you can quote multiple posts so I think it's a screenshot.)