I normally see that from engineers using "O(x)" as "approximately x" whenever it's clear from context that you're not actually talking about asymptomatic complexity.
I've always thought it was like this, maybe I'm wrong:
O(some constant) -- "nearby" that constant (maybe "order of magnitude" or whatever is contextually convenient)
O(some parameter) -- denotes the asymptotic behavior of some parametrized process
O(some variable representing a small number) -- denotes the negligible part of something that you're deciding you don't have to care about--error terms with exponent larger than 2 for example
I've always thought it was like this, maybe I'm wrong:
O(some constant) -- "nearby" that constant (maybe "order of magnitude" or whatever is contextually convenient)
O(some parameter) -- denotes the asymptotic behavior of some parametrized process
O(some variable representing a small number) -- denotes the negligible part of something that you're deciding you don't have to care about--error terms with exponent larger than 2 for example