I think the parent comment is using "compressed" to mean "being forced elsewhere" as opposed to the more typical "being forced into having less volume" which would be exactly what you're also saying. I don't condone imprecise language but I'll give the benefit of the doubt because it's pretty intuitive that water is hardly compressible.

Think about using a compression bandage or compression socks. You're not literally compressing, you're just squeezing the flesh and it goes elsewhere.