みんなで笑った　ー who made what laugh?


ok so, i'm reading デューク and there's a line that says

> その格好がモップに似ていると言って、みんなで笑った。

with my limited comprehension, i'm unsure of whether this means

  * everybody laughed that he resembled a mop.
  * i laughed when people said he looked like a mop.
  * something else completely 

i read [this](https://japanese.stackexchange.com/questions/15486/how-do-i-
express-this-made-me-laugh/15516#15516) which is what made me think my first
translation was probably wrong, but i'm still quite unconfident on the
matter...




The more context the better (we don't even have a subject here), but I would
understand it as: _everybody laughed_

The linked question is a bit different, it is about 笑わせる which is a causative
form - it's about making (or letting) someone laugh (and I believe これ vs みんな
can also make a difference).

Here, you can say で marks a way how the verb was performed and that is "as
everyone".

It is similar to other constructs like 一人で (by myself, alone)、家族で (as a
family), ...

