It measure something like 2 to 3 cm. And I think the photos show the aspect of it alright.
No interactions present.
We had a conservatory shaded by a Bramley Apple tree. Speckled Wood butterflies 'danced' in the shade & often came into the conservatory, sometimes laying eggs on the plants (mainly zonal pelargoniums). They seemed quite territorial & would chase off others of the same species. Pelargoniums weren't listed as the caterpillar's food plant but mine were certainly chewed!
Speckled Woods do take up and defend territories, chasing away other butterflies and insects, must be great to see that at close quarters. They usually lay eggs on grasses, which is what the caterpillars feed on, so I'm surprised they were taking an interest in your pelargoniums.
Entomologist and biological recorder
That's true about them being territorial, they chase any white butterflies that try to sit on the same bush!
I thought it was enjoying the camera because it wouldn't fly far at all! and it would keep still for the nice shots, but I guess it was too happy there to move. :)
Lat/Lng: 51.415238660055, 0.017242580652237
OS grid ref: TQ403703
Likely to be on my backyard