Is it safe to plug a power strip into a SurgeMaster outlet?
As you discovered, this is just another cheapazoid power strip, but in a different &quot;form factor&quot;.  The real receptacle is behind it.
I'm being a little harsh on Belkin; they are certainly best-in-class among the cheapazoids.  I would consider them a Tier 2 supplier alongside Lutron and Leviton.  I use it myself.  However, even a top tier power strip (like Tripp-Lite) is still a power strip and is not anywhere near as safe as built-in wiring.
But it's even worse than that
There are two aspects we really care about: Human protection and machine protection.
For machine protection, this setup as illustrated does not have a safety ground, and while safety ground contributes to protecting humans, it really protects machines. You don't have safety ground.
For human protection, what we need the most is GFCI protection.  You can't use a GFCI receptacle at this location, because the bolt-up &quot;power strip&quot; blocks it.  The outlet certainly could be protected by a GFCI device at another location (receptacle upstream, deadfront upstream, or GFCI breaker). In that case the outlet would be fed off the GFCI device's &quot;Load&quot;  terminals. (that's the only thing &quot;Load&quot; should be used for).  You can test that by hitting &quot;Test&quot; on every other GFCI in the house (you're supposed to do that monthly anyway) and see if doing so knocks out power here.
Other than that, Mrs. Lincoln, it can be OK.
Honestly, what really makes power strips dangerous is uber-cheapies, or asking too much of the power strip.  As I said in the other question, chaining power strips is fine if you don't load them very hard.  This is all about &quot;know your amps&quot;, which most people have no clue about, so, skill up a bit :)
It goes without saying that a cheap Chinese power strip won't handle as many amps as a quality unit, and one which lacks a competent UL* listing won't handle any amps safely at all. Look at any of Big Clive's teardowns on Youtube to see how that is.


* Other agencies on the trusted list of NRTL's would also suffice, but never CE unless it's bought at a reputable bricks-and-mortar store inside the EU.