This article appears as part of the Unspun: Scottish Politics newsletter.

In the newspaper world, the saying 'a picture is worth a thousand words' is sometimes used by photographers to gently remind reporters and editors of their importance in the newsgathering process.

The phrase means that an image can convey multiple dimensions and an essential truth about something in a single instant and in a way not even a lengthy piece of written text can.

Many believe the adage dates back as far as Leonardo da Vinci, though its modern day usage is commonly accredited to the American advertising executive Fred Barnard in 1921.

It came into my mind after going along to the by-election campaign launches by the SNP and Scottish Labour, held not far from each other in Rutherglen on Wednesday morning, following the ousting of former MP Margaret Ferrier in a successful recall petition the day before.

The events immediately struck me as very different and getting back to my desk I started looking through the pictures taken at them by The Herald photographer Colin Mearns.

Two images stood out for me and seemed to portray a changing dynamic in Scottish politics. The first was of Scottish Labour candidate Michael Shanks fielding journalists' questions on his own – his party's deputy leader Jackie Baillie was across the road speaking to MSPs and activists – and was not in the photograph.

The Herald:

The second which caught my attention was at the SNP event. Here party leader and First Minister Humza Yousaf was doing most of the talking to the reporters while the candidate Katy Loudon sat behind him with a rather glum look on her face.

The Herald:

Yes, there were other pictures taken at both events.

There were ones of happy SNP and Labour MSPs and activists alongside their respective candidates holding up party signs, each group appearing confident that victory lay just ahead, another of Mr Yousaf and Ms Loudon smiling and dancing, apparently without a care in the world.

But I alighted on the two more candid pictures, taken as glimpses behind the scenes, which to me gave insights into what is really going on in Scottish politics and how the two rival parties are faring.

I don't know what was going through Ms Loudon's mind at the moment caught in time by Mr Mearns, but the image was not a happy one.

For me it summed up the mood which pervades the party. To anyone with even a passing interest in Scottish politics, it's clear the SNP have much to be rather unhappy about.

The police investigation into SNP finances hangs over the party and appears to show no signs of going away soon; the exit of eight of its MPs at the next general election; problems in government on health and education; divisions within its Holyrood group of MSPs, some over the Bute House Agreement with the Scottish Greens, all point to a party not much at ease with itself.

There's also maybe the hardest challenge of all, the failure to deliver a repeatedly promised second referendum and with it a lack of a clear route to independence. It's a difficult problem, of crucial importance to the party and one which has not been satisfactorily addressed. It's critical too to the party's fortunes given the central role of the independence message in both the autumn by-election and the general election, expected next year.

In contrast, the photograph of Michael Shanks surrounded by reporters, appearing quite happy to be fielding thorny questions on the differences between UK and Scottish Labour on the bedroom tax, the two-child benefit cap, on his party's ultimate support for Brexit and unwillingness to even contemplate joining the single European market, conveyed a more confident and upbeat position despite the difficulties which such differing stances between Labour north and south of the Border must mean.

UnspunThe three reasons why Margaret Ferrier's constituents removed her from office

The picture seemed to say 'we know we're far from perfect, but we are happy in our own skin, we're listening and making progress'.

Some may say it's rather easy for Labour to look positive at the moment given the circumstances which overshadow its biggest political rivals in both Scotland and the UK overall (with the Conservatives also fairing badly in the opinion of most voters).

But that is beside the point really.

In the contest of imagery Labour clearly won on Wednesday. The Shanks photograph conveyed a party on the cusp of a long awaited revival while the Loudon picture reflected the SNP at a low ebb.

SNP supporters didn't like the juxtaposition. Howls of protest from some less thoughtful backers greeted my posts about the two photographs. Abuse was hurled my way.

Some people stepped in to thankfully point out I was simply doing my job as a journalist reporting and interpreting events of the day.

To me the reaction to my observations itself though does prove my point that – like it or not – the SNP are on the back foot in this by-election, and many of its supporters are tetchy.

And it also suggests that over the coming weeks until the vote takes place in October this is a campaign which is going to be one of the SNP's most difficult.

...enjoyed the article? Sign up for free to the Unspun newsletter and receive it directly to your inbox every weekday night at 7pmClick here 👈