Hmm, yes~ Did he buy her those, or did he have someone else go do it, or just tell her to buy something sexy. Regardless, now I'm imaging Lord English going out and buying lingerie for the Handmaid. Shenanigans would happen.
He'd probably have to go out twice. At first he'd forget her measurements and just wishfully buy the largest panties available. Though the Handmaid probably wouldn't feel too insulted, since she was taught bigger is better. Though if he did buy super large frilly panties, the people at the store would imagine he has some weird hobbies. But in the end, the Handmaid would get her sexy underthings, and they could both enjoy them together.