David Cameron took the stage at an election rally in Wadebridge, Cornwall this evening. He was surrounded by supporters waving placards. From the pictures, it seems there was a real sense of excitement about the Conservative party.

But here are a couple of photos taken from a perspective that's a bit, er, different.

The PM is currently holding a rally in Cornwall, in what appears to be a massive cow shed pic.twitter.com/eJh6RrnsQ6

— Niall Paterson (@skynewsniall) April 7, 2015

To give you a better idea of the size of this barn, and the size of the rally, the event is entirely behind this bus pic.twitter.com/4SPBJ8B1X7 — Niall Paterson (@skynewsniall) April 7, 2015

Well, it's impressive enough the Tories found a barn sufficiently large for them to fit a bus in it, let alone a barn so big you could fit an entire fleet of buses and your activists in it.

But what's more impressive is that this isn't a rally at all, is it? It's not even a rally in the sense that the massive barn, which is actually the Royal Cornwall Show ground, normally sees in terms of vintage steam rallies and so on. It's certainly not one of those rallies that parties hold at conference time, or indeed a rally in the traditional sense where normal people turn up. This appears to be a rallying of party activists towards the cameras, a photographic backdrop for the Prime Minister featuring the converted, not the curious.

This isn't unusual for any party. Labour's speech from Tony Blair this morning seemed to have attracted along the usual crowd of people who didn't like anyone who disagreed with or indeed questioned the former Prime Minister. The parties summon these applauding placard-bearers from their membership lists or sympathetic organisations in order to create an atmosphere for the cameras and evening news bulletins, rather than to persuade anyone present at the 'rally'. It's a pragmatic approach to politics as it focuses on the millions who will watch the party leader speaking, rather than the hundred or so people in the barn or carefully-chosen speech venue. But it probably also contributes to the rather flat overall atmosphere of this election so far. We're a long way from the organic excitement of the Scottish referendum.