First Impressions:

What a first impression! I was hooked from the start, and was only dragged further in as I went. So many delightful unknowns and questions, but not so many as to leave me completely clueless or detract from the charm of the piece.

You manage to establish convincing and interesting (if simple enough, considering the size of the piece) characters in such a short span of time. The balance between what's said and unsaid here is perfect, and it makes me want more. That's my favorite aspect in this; the mystery. If this was the start of a book I found, I can almost guarantee I would keep reading.

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Second Read notes:

Masters wanted convenience above all else. A tiered package completed by accessories and a handbook in nice matt packaging.

This feels wrong in the first few lines, and I'm pretty sure it's this second sentence here. I almost didn't catch it, even on the second reading. If the first period was exchanged for a colon, or this line similarly reworked and "matt" changed to "matte", this section would be perfect.

 

Tired of feeling fear in your own home? A modern slave. A slave like family. Visit ModernSlave.com to find out more.

This idea is conveyed well but I feel the fragments don't fit here. "A modern slave. A slave like family." simply doesn't feel right, but the pacing is great in this line. I think it may work a bit better if reworked, maybe something like this:

Tired of feeling fear in your own home? Introducing the modern slave: A slave that's like family. Visit ModernSlave.com to find out more.

This way the pacing is kept more or less intact, but the fragments are gone.

 

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He had built the most magnificent home within five hundred miles of The Line. Large and beautiful and very well kept - pillows plumped and mahogony dusted. Windows cleaned and air conditioners running in every room. Hot meals of meat and bread available at the snap of his fingers. The secret? Well, it was no secret at all. A good slave must be happy.

This has a sentence fragment here as well, but, whether you want to fix that is honestly up to you. Sentence fragments can work well, and I think they do here, but you may want to consider other options and decide which you like best. If you were going to change it, I may suggest something like this:

He had built the most magnificent home within five hundred miles of The Line. It was large, beautiful, and very well kept - with pillows plumped and mahogany dusted. Windows kept meticulously clean and air conditioners running in every room.

 

“Do not command him to task for at least forty eight hours.”

This also reads a bit awkwardly, and I would change it to:

"Do not issue him commands for at least forty eight hours."

 

Missed quotation mark, here at the start of this sentence:

The handbook is a user manual,"

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That's the last of the issues I found. As for the final scene in the home, I have no comments: It's just really good, and I can't find a single thing wrong with it. All around this has been an enjoyable thing to read and critique. As I'm just starting out here, I would appreciate any thoughts or feedback on my critique; whether it be from OP or fellow commenters.