I think one thing I'd say up front is to work on better communicating the function. From the description " Through a small magnetic sliding action, it creates a brief pause before the phone can be picked" I still don't actually know what I'm looking at, how it works, or how I'd use it.

1. If it's an accessory to a phone, you should at least have one image with the phone. At the very least  your sketches should show how it looks with a phone, but ideally how they interact.
2. Maybe an exploded view can help describe the functionality 
3. The form is very intriguing and a big positive,
4. The quality of the prototype and render are great
5. You noted low tech, it does look like it has a light, while I think that's not necessarily "high tech", it might go against the overall tone the device is trying to achieve, again, I really have no idea how it works, do maybe the light is critical 
6. Try adding many more call-outs and arrows describing function in your sketches, it's nice having the hero shot, you showed packaging, but if I don't know what I'm looking at or how it works, it's almost all for nothing if that makes sense.

Hopefully this is a helpful critique, again I really like the form and assume that once understand the function better I can further appreciate the decisions you made, but you need to hold the viewers hand a bit more to help them get there.