That would please the rank and file, who like to hear these things before the media are told.
The second is she is waiting to hear what Shaw's final decision is – he has said he is "inclined" to stay in the ring, but is talking to members and MPs before a final decision. If Shaw decided to withdraw, she would almost certainly stand.
The question is whether Swarbrick would force a contest against Shaw.
So the third possible explanation is that she is taking soundings on whether she has a chance of toppling Shaw in a vote.
Of them all, the second option is the most likely – if Shaw stays, Swarbrick would not contest it.
But if he does not, the other names doing the rounds are those of newer MPs Elizabeth Kerekere and Teanau Tuiono – and there are suspicions they are partly behind the antics to reopen nominations.
Swarbrick will not sit by if those are the only names in the race, and she would have the greatest chance of holding the Green vote up.
If she has no intention of forcing a contest against Shaw, she needs to make that clear quickly and put Shaw out of his misery.
Misery is what he will be in – and so will Labour.
The party a leadership rumble would be the most disastrous for is not the Greens, but Labour.
In little more than a year's time Labour will be fighting an election and the main contest will be economic credibility.
As things stand now, it is almost certain Labour will need the Greens, and National will need Act.
For that to be Labour and the Greens, Labour needs voters to be convinced that the Greens are not going to start changing the ground rules on them.
Both parties need to look like a stable, united force – within themselves and together.
It may well be that this subsides to nothing and in seven days' time, Shaw remains the only nominated name and those pushing for change realise no other strong candidate is coming through and give up.
But the Greens have a vote on the co-leaders every year. Next time they have one an election will only be a month or two away.
Leadership changes are destabilising - just ask the National Party who have produced something of a training manual on the right and wrong ways to go about it (mainly wrong).
Last time Shaw was challenged it was by a party member who had no chance. Shaw won convincingly, but it would be a different matter if a sitting MP put up the challenge.
Many hold the view that Shaw will hold on. The vote to reopen nominations fell well short of 50 per cent. But if Swarbrick does decide to stand against him that could change.
Shaw will have a nervous few days – or weeks – ahead. Because the Green party membership are consistent in one thing: being unpredictable.
The Green Party has fewer pews than Labour or National, but it is still something of a broad church. Its caucus has traditionally included both those whose focus is on the environment and climate change, and those whose focus is on social ills: from poverty to drug reform.
Its co-leaders have tended to reflect that as well, at least in more recent years. Over time, the social activism pews have become of more importance (and strength) because other left-wing social parties have disappeared, such as the Alliance Party. The Greens and Te Pāti Māori now cater to those views.
In recognising that, Labour could have been more helpful.
This term the Greens have been in a desultory position: neither in nor out and bordering on irrelevance. They have tried to claim credit for some moves by the Government but when it boils down to it Labour simply doesn't need to give them the credit.
Next term will be a very different matter.
Many Green MPs want a coalition two-party government, putting behind the years of being sidelined to get another party on board. It would give them more influence than they have ever had before and they are on the precipice of getting it.
However, coalition also means more restrictions than they have had before in terms of openly opposing or voting against measures that do not sit easily with their party's rank and file.
Shaw will be justified in feeling under-appreciated after his years of work to try to ensure the Greens could be seen as a credible force in Government.
He has done what many considered impossible: getting almost unanimous political support for the Government's climate change package. The significance of that should not be understated. It means that even after Labour loses power, the climate change policy should survive largely intact.
But compromise always comes at a cost – and clearly some of the Greens think that cost should not be paid.
