853875 Sweet Mayhem Pod has not yet been listed at shop.LEGO.com but it is now starting to show up in brand stores and I picked one up in Leicester Square after seeing the film on Saturday.
Sweet Mayhem is one of the new characters in the film, although not the most outstanding (that's the queen). However she is certainly going where no Friends figure has gone before. In the two boxed sets she appears in, 70824 Introducing Queen Watevra Wa'Nabi and 70830 Sweet Mayhem's Systar Starship, she's kitted out with a funky space helmet and suit. They are not included in this set but her fantastic sparkly hairpiece is.
Some pods are packed in polybags but this one, and 853874 Emmet Pod, the other TLM2 pod, are in blister packs, which to me at least make them less collectable.
Like many of the other pods this one has a lenticular image on the front, which in this case shows the film's title from one direction and Sweet Mayhem in her space suit from the other.
Among the handful of parts are the new 1x1 heart tile and 3x3 heart plate. I'm not exactly sure what it is that they build but it looks quite cool and colourful. I think the black dishes are speakers.
The Sweet Mayhem mini-doll in this set is unique (from BrickLink's cataloging point of view) in that she's not kitted out in her space suit but I believe she's otherwise identical to that in 70830 Sweet Mayhem's Systar Starship!.
Her hair is exceptional. It's produced from a soft material and finished with a shimmery, glossy paint that reflects different colours as you move it about.
She can sit in the left hand side of the pod and do whatever it is she does in there.
Pods are a great way for kids to carry their favourite figures around with them and I am sure Sweet Mayhem will have a lot of fans when she's been seen in the film so this is bound to be a popular little set, once it's more readily available.