Do you mean a routine maintenance issue becomes a safety issue when it is intentionally disregarded?
While that certainly could be the case, it doesn't automatically follow. Further, there's absolutely no evidence of that being the case here.
In this specific case, a non-structural part is attached with a number of fasteners of which only 2 appear to be missing. Assuming no further loss of fasteners, the airplane could continue to operate with no safety degradation. Without having a MEL/CEL to check, it's entirely possible that the airplane would be allowed to operate with the fairing missing with no degradation of safety.
That is not to say that this airplane should continue to be operated as if nothing was amiss. Any irregularity needs to be brought to the attention of maintence and corrected or placed on the MEL/CEL.
The OP's question concerned the affect these two missing fasteners have on safety. The OP didn't address how long these fasteners had been missing or what that may or may not say about the carrier's maintenance practices, etc.
Just looking at the pictures, I can't tell if those fasteners had been lost on the previous flight, whether maintenance was aware they were missing and were on the way to take appropriate action, whether a proper maintenance sign-off was already in the log book authorizing flight with them missing, or even if lots of the other fasteners were missing. All I can do is answer the OP's question - do those two missing fasteners, by themselves, make the airplane unsafe. I stand by my answer that they, by themselves, do not. In other words, if I were the Captain of that airplane and found out
in flight that those two fasteners were missing, I would not hesitate to continue on to my destination. I would not throw my hands up and scream "This airplane's falling apart, we're all going to die!!!"
Maybe you can deduce much more from those pictures and therefore speculate that the fasteners had been missing for weeks/months/years, and are therefore indicative of sloppy maintenance, which furthur indicates that other maintenance is not performed, which leads to the conclusion that this airplane is unsafe. But that would be nothing but speculation.
Jim