i have seen a lot of dog faced puffers do this...
They will actually roll over when you put your hand in the tank(almost submitting to you) and over time you realize that they want you to rub there bellies.. (which doesn't really feel like anything, the skin feels as thin as tissue)
I had an all black dog face that i just lost do to ick..(a really expensive one too
) When he was in QT (under hypo) i walked into the room and seen him puffed up.. The first 2 times i seen it, he stayed puffed up for 15 mins or more.. By the 3rd time i stuck my hand in the tank and rubbed his belly(figured it wouldn't hurt anything anyways) he deflated immediately..
With that being said i would almost say it actually relaxes the puffers..
I probably wouldn't be so excited to rub a porky tho..