I should imagine it's described as "masculine" partly because the word operates as a kind of code. JM is known mainly for her fresh, floral type scents. So "masculine" means it's a bit more "crisp white shirt" than "Cath Kidston".
I say that with a touch of irony; I'm a big JM fan. And I love the florals. Am wearing "Vintage Gardenia" as I type.
"Chanel no 5" is lovely, too.
JM's scents tend to be what is described as "linear", which means they smell modern, to our noses, and they are easy to wear throughout the day (not overpowering, "polite", quite straightforward - you can see why they get sent up as "ladylike" and "English" - all good things in my book).
Chanel no 5 is a different sort of scent. It's quite complex, and smells "older". One shop assistant informed me it wasn't so popular with younger women .... But it is a lovely, sophisticated, complex classic, that unfolds its components as you sniff it, and is intriguingly multi-layered.
Rather nice choice from your dh.
Could you not have both ...? You may find that, on one day, Lavender and Amber expresses your mood, on another, Chanel no 5 invokes something of your inner landscape ... .