WARNING! THERE MAY BE UNMARKED SPOILERS!
- Accidental Aesop: In light of "The Curse of Peladon" being a pro-EU tract, the timeline here established turns this episode into a Brexit tract.
- Captain Obvious Aesop:
- The anvilicious "slavery's bad, mmmmkay?" aesop seems to have been a deliberate attempt at amends for the Fridge Horror of the Doctor basically saying "okie dokie" when he discovered the Ood slaves in "The Impossible Planet"/"The Satan Pit" and left them to die at the end of the episode. This is the main reason they made "Planet of The Ood", to address that fact. It's even lampshaded when Donna points out how uncharacteristic it is for the Doctor to not help the Ood. The Doctor points out he was battling Satan at the time and thus a little busy. Then he admits that he owes them one.
- One only slightly less obvious (but in some quarters probably still necessary) might be: "Even if a people doesn't look like you, and seems more primitive than you, that gives you no right to exploit them."
- There's a slightly more subtle Aesop at work as well. At one point when Donna's railing against the institutionalised slavery represented by the Ood, the Doctor points out that most of the clothes she's wearing at that very moment were manufactured in sweatshops by people living only a few steps above slavery. It suggests that although people in the west intellectually know slavery is bad and wouldn't tolerate it when they're directly exposed to it, if it's out of sight and they benefit from it they're likely to not give it much thought. The people overseeing the Ood Operations plant even say the same is applicable for the Ood.
- It can also be interpreted as "revolutionary violence against an evil system is morally justified".
- Harsher in Hindsight: It's sad for Donna to hear the song of the captured Ood, but it's even sadder for the viewers who have seen the end of the season. Donna can't handle something humans are not supposed to experience, and the Doctor blocks it for her.
- The Doctor compares the severance of the Ood's hind brains as akin to a lobotomy, and then furthers the point by saying that Donna would be like a processed Ood if someone took her memory and emotions, just as he would have to do her in the season finale.
- In spite of the assumption of broadcast order and early intentions to bring back Ida Scott, Big Finish's Torchwood audios curiously went on to date the events of The Impossible Planet *after* those of this episode (the former's given date of 43K2.1 being later explained as another dating system's version of 4221, while Planet of the Ood is set in 4126). Which means that despite the implied happy ending here, not all Ood slaves were returned to the Ood Sphere after all, be it through ignorance or malicious defiance of their revolution...
- Hilarious in Hindsight: The wristwatch communicators that some of the characters are shown using don't seem too far fetched now that Apple and Google have introduced smartwatches capable of making phone calls independent of a smartphone.
- Magnificent Bastard: The Ood Brain is the conduit for the Ood's telepathic network, that will commandeer Oodkind in dire times, with its main representative being Ood Sigma. After the Ood were enslaved by humanity, for 200 years the Ood Brain was left helpless and unable to act. The Ood Brain finally got its chance for revenge when a human Ood activist lowered the telepathic force-field and started the Ood Rebellion. The Ood Brain transmitted a Hate Plague to all Ood in range which afflicted them with "Red-eye", turning the usually peaceful Ood murderous and vengeful. The Red-eyed Ood began killing the humans they once served, going from discreet murders to escalating into all out war. Eventually only Ood Sigma remains, where he feigns loyalty to Corrupt Corporate Executive Klineman Halpen, preparing him for the ultimate punishment of feeding him Ood graft and turning him into an Ood himself. With the root cause of Ood enslavement neutralized, the Doctor assisted in "breaking the circle" of the telepathic force-field, reestablishing the Ood Brain's connection and freeing Oodkind from enslavement.
