My son has something like this to store a pistol. The idea is, it is hidden but not locked away to make it difficult to get to quickly, also, unless you know what you are looking for, I don’t thin anyone would recognize this. This is not the one he has so there are probably other brands.
Hey: No offense personally, but those things being advertised - the linked shelf/storage - were the absolute worst thing to ever happen, and posting it here isn’t helping. There are many derivatives of the web-based firearms storage ‘solution’. They’re all laughable. Don’t believe for a second that many criminals don’t know what they are.
I was in security and consulting for a long time, and at one time not so long ago you had to have such a thing custom built by a contractor, and no different than the little 4 words most everyone misses on the posting page, “loose lips sink ships.”
For example: When having a gun safe delivered, ensure the truck is not emblazoned with the name of the seller and ask that they camouflage the box (there are several ways of doing so which I won’t put in public forum), and never, NEVER put valuables’ packaging in the recycle at your house. Safe’s can be camouflaged in situ as well, in ways only a professional thief would ever recognize.
Firearms and high-value items pose unique challenges.
I’ve seen these ‘shelf’ & ‘coffee table’ things advertised & promoted by a local reserve officer who owns/operates his own security company; while I was on social media I berated him incessantly until he ceased their promotion.
He should damned well know better, and anyone reading this should know better than to buy that crap.
Despite my own wife’s opinions, if my weapon isn’t on me, it’s on my counter within 3 feet of me. It is impossible to breach my door without giving me ample warning. I have no children in the house.
Each individual situation is definitively unique - to state nothing of local/state laws - and it’s not possible to answer the OP’s question without another 20 or more questions and a visual assessment of the situation.
Seek out a local professional for such advice; I couldn’t offer a cogent solution in-forum and would normally not presume to do so. It’s unprofessional and potentially deadly.