Doubles: returning side net player jumping sideways loudly right during serve - hindrance?

Watching a local tournament right now, and the returning side’s net player jumped sideways twice loudly (like he was faking a poach) right as the server was serving. The serving side said they didn’t think that was allowed and asked him not to do it, and the returning side said “well go call the official then”. The serve was out.

To me it looked like a hindrance since obviously you cant poach the serve and it seemed to serve no purpose other than being a distraction. Thoughts?