Well, isn't that the whole point behind not wanting them to have a unique and recognizable design? If a thief doesn't know what a hardware wallet is, then they just look like a slightly unusual USB stick, key fob, remote control, etc., and are unlikely to attract any great attention.
As ranochigo said, in order to make the device blend in you must also put it close to others or out in the open, and that's where the juice, dog mistaking it for its toy, kid playing around accidents happen. But if you avoid this and you put it in your safe I doubt (although thieves have shown to be pretty stupid sometimes) someone who breaks in it will think this is just a remote or a useless USB stick that has nothing of importance on it.
So you will need a place where to blend in as nothing special but at the same time a place safe enough to avoid daily house accidents or incidents
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While I agree that having a device with "Bitcoin storage" with golden 1-inch letters all over it's a bad idea at a certain point and more importantly the value held in it the design will lose a lot of its importance in preventing theft.
Trezor looks somewhat like the remote control for the garage (?)
To me, it looks a lot like the old glucometers we were using, two buttons, a small display, and quite rugged compared to other small devices I've encountered.
My remotes for the gates at home and the arms barriers at work are far simpler than it.