What does it mean to remark on what is obviously the case, as Zoe does when she states, flatly, that "the camera's on"? 

Here's that section of the transcript again (I'm using Transcript 4, without all the red text or the explanation of the symbols; click on notation if you need to jog your memory of what the symbols mean).

17		(6.0)
18 →	Zoe	th' camera's on.
19	Lyn	>yes<
20		(1.8)
21	Zoe	w'(h) are you ta(h)lking to it while you
22		wORK?
23	Lyn	no:,
24		(.5)
25	Lyn	[heh heh ºheh hehº=
26	Zoe	[hh what ye' DOINg then
27	Lyn	=hahh hahh hahh
28		(1.0)
29	Zoe	what's the ↑point:h
30		(1.5)
31	Zoe	↑oh ↑god (.) look what ↑I'm wearing

Noticing.

We might be guided by something already known to CA - that making a remark with no 'news' value whatsoever can have specific interactional consequences. 

Look at this example, in which the caller 'notices' that the receiver's line's been busy. 

(from Pomerantz, 1980)

1		[phone rings]
2	Receiver	Hello::
3	Caller	HI:::
4	Receiver	Oh:hi:: 'ow are you Agne::s
5 →	Caller	Fine. Yer line's been busy
6	Receiver	Yeuh my fu(hh) - 'hhh my father's
7		wife called me [...etc..]

Caller says 'yer line's been busy' - but that can hardly be news to the receiver, who is presumably just the person responsible. What is interesting is that the caller's remark prompts the receiver to give an account of why the line was indeed busy.

In line 6, the receiver responds to caller's line 4 as if it had been an explicit request for an explanation of why the line had been busy. The caller's "noticing", then, has worked to make the receiver accountable.

Here is another example, from the work of Emanuel Schegloff. As in Lyn and Zoe's situation, one party (Carol) has just come into the room.

(From Schegloff, 1988, p 119 and 122; overlap notation simplified)

151		[door squeaks]
152	S:	Hi Carol. =
153	C:	= [Hi::
154	R:	[CA:ROl, HI::
155 →	S:	You didn't get en ice-cream sanwich,
156	C:	I kno:w, hh I decided that my body didn't
		need it,

S, like Caller and like Zoe, is 'noticing' something patently obvious. And Carol, like Receiver, responds with an account - an explanation and a justification for why it is so. She did not bring back the ice-cream sandwich (whatever that is) because 'her body didn't need it'.

So with that background CA work, we have a particular lever we can use to get a grip on what what Zoe and Lyn are up to.

What is Zoe doing with her 'Noticing'?

Zoe notices that the camera's on, so an account is wanted. Things get interesting at this point. You'll see that Lyn's next turn is pretty minimal - a bare 'yes'. Now that might do as an account, but Zoe would be within her rights to treat it as rather inadequate.

And she does. Here's a reminder of what happens:

17		(6.0)
18	Zoe	th' camera's on.
19	Lyn	>yes<
20		(1.8)
21 →	Zoe	w'(h) are you ta(h)lking to it while you
22		wORK?

At line 20 Zoe leaves a full 1.8 seconds (a significantly long time in a conversation) for Lyn to expand, or come up with something that looks more like an explanation. It doesn't come. So we hear the question in next line (21) as a more specific, targetted attempt to get an explanation. This time, Zoe casts it as a yes/no question. The question makes clear the kind of response that Zoe is looking for, but that Lyn has failed to give so far.

What have we learnt?

We could go on further, and see how far Lyn and Zoe get in reaching a mutually acceptable explanation for the camera being on. If we were doing a full-blooded analysis of this episode, that's one line we could take. If you wanted to, you could have a go yourself: look and see if Lyn offers explanations, and if Zoe accepts them. You might go on to look and see, for example, if all the business about the camera being on might help explain what Zoe means when she says "oh god look what I'm wearing" in line 31.

But we've done enough for the exercise, if we've managed to illuminate what interactional meaning such an apparently neutral observation as 'the camera's on' has had. Reports aren't always just reports; like all language in interaction, they can accomplish things which aren't obvious at a first glimpse.

If you'd like to see another exercise in analysis, click on analysis 2 'teasing'.