This image you see here was taken from my phone, sorry it isn't the best quality and the poor lighting, but you get the idea, hopefully. This is from Catalogue.
What is intriguing about the painting is that, I believe Watt contributes three styles in one painting: realism, surrealism, and expressionism. Realism because you can pretty tell that it is them. Surrealism because in a way Watt have Neil's head slightly tilted in the painting, which can be defined as another emotion possibly, where as in the photo he looks all serious and his head is straight forward. Expressionism because if you look at the photos together, you can definitely see some differences. In the painting, there's a small pot on a shelf on the back of Neil's head. The actual photo you can see small objects and a flat pot farther away from his head. The portraits inside the painting and the photo are different: the painting has a full head of the image of a face, the shape of the portrait is a square shape, plus it is darker than the actual portrait in the photo itself and the portrait in the photo is a rectangle. The photo has the person having his hand on his forehead. Which probably depicts a difference in emotion or mood she was in when she did the painting. The proportions are a bit exaggerated on the painting:the shelf, the small monument column is thicker than the objects in the actual photo; moving in a forward like position. The squarish shape was added I guess to make it more good in space. When you also look at the image very carefully, Neil's emotion looks more calm in the portrait; his shirt gives off a bluish-green colour, while the photo gives off a grayish-light periwinkle colour. The wrinkles in his shirt also looks less definite in the portrait and then the shadow where his right arm is location looks overlapped somehow. The actual photo is the opposite. Neil's head is not even the same size in the painting as well. His hair looks darker and thinner, while the photo the hair in front of his head is poofy. Chris emotion looks about the same, could still have a different feel than the actual photo. Chris's pants looked blended in the shadow and his face is darker in the portrait and his head is slightly bigger, while in the actual photo, he's lighter and his head is small. The object behind Neil seems to pop out more than in the actual photo. Even the mirrors don't reveal the same reflection the colours in the painting looks like a tan like colour, while the other photo it gives off between cream and ecru. You can't really tell what mood they were when the photo was taken, but as an artist, you tend to over think things and convey or trying to convey what you see and putting it on a canvas; or in some cases, by the looks of the painting, if the characters are in some calm mood, Watt was more likely in a calm mood as well. By the looks of this painting, I think it's oil on canvas or acrylic, it didn't say on the book. It reminded me of when I don't know what to put in a drawing, just put something distinctive.