It's not an in-universe image. It's from the Dr. Who exhibit at Madame Tussauds wax museum in London, 1982-1986.
Dr. Fan "The Gene Lantern" posted a similar image on the Dr. Who North America fan forum:
:
Clues: a) It was unlikely that the author would have had an screenshot from the TV series given the technology of the time, b) the image was not from either of the 1960s-era movies, and c) Daleks don't have human companions, and the people standing at the right rear looked like tourists looking at a display over a barrier. Only a few exhibitions were listed at https://en.wikipedia.org/wiki/Doctor_Who_exhibitions prior to the 1986 publication date of the paper, so this had to be Tussauds, and there was a picture. (Based on Gene Lantern's reflection, the upper right in the image appears to be a mirror.)
And there's yet more detail on the quirky design of the prop on display from Dalek 6388 (which has a lengthy history of all the Dalek props and design changes):
Dalek Six’s shoulders, neck and dome were paired to the Exhibition
skirt to become Dalek Six-ex, A disc was added to the top of the dome
which sat around the pivot and the lights were replaced. Despite
Madame Tussauds being a showcase for mimicry, the prop was
inexplicably painted in a light blue finish with silver and black
highlights – a colour scheme totally unheard of in the entire history
of the programme. At some point during its stay the lights were
changed again to the more usual ‘sidelight’ type although these were
encircled by discs similar to that of the new addition on top of the
dome.
![light blue Dalek](https://i.sstatic.net/tuHot.png)