This marks the first time Samantha is seen wearing her witch's flying suit.
The premise of this episode is used again very late in season 8, substituting mattresses for soup in A Good Turn Never Goes Unpunished (1972).
This episodes were filmed months before air dates and were then broadcast out of filming order. This is very evident here, as Liz---once again---has her original broader, upturned and more impish nose tip, and her cheeks are back to plump and youthful. Whereas in episode 4, her cheeks were conspicuously narrower (having been sculpted and sporting newly acquired cheekbones), her nose had been refined and her jawline had also had work done which left it very defined.
At approximately five minutes into this episode, Samantha and Darren are in the den. Samantha is wearing a peignoir set style of flowing nightgown. As Elizabeth Montgomery momentarily places her arm across her abdomen it appears to show a bit of a baby bump, or post-baby bump.
There is a full bathroom attached to the den. It is in an odd location. The back wall is the same wall as the entrance wall. Putting plumbing there is not logical.