More impressive than the answer here is the safety precaution NileRed took to avoid dying while seeing what cyanide really smells like.
Spoiler: bitter almonds, which contain high levels of cyanide, are far closer to smelling like cyanide than regular almonds. It turns out that cyanide in crystal form doesn't have much smell at all. Prussic acid, or hydrogen cyanide has a sort of chlorine smell, apparently.
It turns out that regular almonds do taste a bit like cyanide, even if they don't smell like it:
After posting this video, I got a few messages from people saying that in their experience, cyanide DOES smell like almonds. So, I spent an hour tonight doing some tests, and I think the results are interesting. I did some direct comparisons and the smell of cyanide is distinctly different from the smell of almonds. However, if I EAT the almonds, there is sometimes a faint taste of cyanide. I think this is because sweet almonds still have a very small amount of amygdalin in them, which can release HCN. I don't think it's enough to smell in open air, but in your mouth it can be concentrated enough to be detected at the back of the nose. It's subtle, but it is definitely part of the flavor profile. So, while I still don't think it's accurate to say that it smells like almonds, for some people, it might be similar to the taste. To make that connection though, the person needs to a) be able to smell HCN and b) be particularly aware of that part of the flavor.
Image: YouTube / NileRed