Of course, with the slippers Dorothy becomes West’s target for the bulk of the movie. Does Glinda know/care? Listen to her passive-aggressive read of the situation after West’s smoky departure: "I’m afraid you’ve made rather a bad enemy of the Wicked Witch of the West."
Now if Dorothy were the actual teenager Judy Garland was, and not the innocent/gullible 10-year-old she was playing, her response would have been: "I’ve made her an enemy? You did it, you bitch! I didn’t ask for these shoes!"
(It is true that, had Dorothy remained in her farm clodhoppers, West might have killed her for revenge or just out of spite, so Glinda is at least protecting her pawn by going all Carrie Bradshaw on her. As I said, dumb like a fox.)
Can Glinda Be Trusted?
Whatever Glinda’s motives, she’s maddeningly evasive. Evil and murderous as West is, at least she’s direct. She doesn’t pretend to do or be anything she isn’t: hungry for power and frustrated into sarcasm. When she says later in the film that it’s kind of Dorothy to visit her in her loneliness, she knows she’s being nasty/scary. If Glinda said the same line, we couldn’t really be sure she wasn’t indulging in self-pity.
Glinda stokes the plot engine with her next move, sending Dorothy to Emerald City to ask for a ticket to ride back to Kansas from the “great and powerful” Wizard of Oz. In the Glinda’s-a-well-meaning-cluck reading, she believes the Wizard is actually as powerful as he’s reputed to be. She’s done all she can, arming Dot with bewitching shoes of red, and is now passing her up the chain of command.
Or: Glinda knows (or at least suspects) that Oz is a fraud, so she sends Dorothy on ahead to find out. This also gets Dorothy out of Glinda’s hair for a while, allowing her to do some research on the ruby slippers that may be helpful later on. She does keep an eye on Dorothy’s progress, counteracting West’s deadly sleep of the poppies with a snowfall. (I’ve often thought this was about turning the poppies’ opium into heroin.)
Glinda as power player and Dorothy as pawn also provides a more plausible explanation for Glinda’s final insult, when she reveals that the shoes would have taken Dorothy home at any time. Her stated explanation – that Dorothy wouldn’t have believed this earlier on – has always stretched credibility. Really? It’s not even worth a try?
So Glinda just seems to be condescending to Dorothy in this next-to-last scene of the film. In actuality, she’s covering up – in her patented passive-aggressive way – her own previous ignorance of the slippers’ traveling power. Had Glinda known about the go-home magic, and had she somehow been able to convince Dorothy to use it, both she and the slippers would have been safely out of West’s homicidal clutches. Of course, the movie would have been 35 minutes long.