I assume they’re making a reference to Lox the food (brined Salmon), so a fish is appropriate.
Think it comes from the german word for salmon, "Lachs", or at least an earlier version of the word.
Swedish is even closer, there it's "lax" [1].
I learned about „lox“ in NYC, a native told me it comes from jiddish, which is kind of a german dialect.
Oh! This is the first time I'm hearing about it. That definitely looks like a missed opportunity.