The dream in the beginning seems also very symbolic, both foreshadowing things that are going to happen, and "backshadowing" what happened in the past (and is explained to us later).
Picard is acting angry or surprised that Data's bet would mean betting everything that Picard has - Picard bet everything he had to be able to save the Romulans... And he lost it all.
"I don't want the game to end"
And of course, this wonderful, hard-hitting emotional line... it shows his particular sentimentality about Data - but it also symbolizes that he isn't really finished with Starfleet or at least what it represented - the game - yet. He still wants to go on another adventure, and towards the end of the episode, he acts on it.
His description of Data's "tell" represents his familiarity with android lifeforms, kinda symbolizing how he is so quick to get behind Dajh's true nature. Interesting to note: Data himself was able to pick up some oddities about Juliana Tainer (Soong's wife's Android replacement, for those that forgot) by visual cues like blinking patterns or the way she played her instrument. Whether Picard's ability in the dream is more representing a metaphor for his detective work regarding Dajh's origin, or literally means he can subconsciously or consciously pick up clues of Android-typical behavior is probably anybody's guess.
I am not sure if the 5 Queens are going to symbolize something upcoming - it could stand for the Borg Queen (and thus just the Borg), it could stand for Q, it could stand for 5 important women (In this episode, if we want to look for 5 significant women, we could take Dajh, her sister, Allison Pill's character, his female Romulan housekeeper and the reporter, but that might be a stretch. It could reference the rest of the season, Seven of Nine or Deanna Troi could be part of it...),or a wild combination of thereof - or really just a cute reference to the past. Maybe someone else has an idea?