After conducting additional research on this claim, I found it to be partly true/ opinion based. Dogs have dichromatic vision - which means they only see a variety of 2 primary colors - blue and yellow. Dogs' vision also operates differently from humans, specifically in how fast they register images. This is why specific programs or “Dog TV” typically operate on a higher frame rate per minute, which is why these videos sometimes seem overstimulating to us humans. Dogs also show a preference for familiarity on screen- like other dogs, squirrels, outside scenery, dog toy noises, etc. While these are some of the reasons dogs might gravitate towards to screen or exhibit signs of enjoyment, the general statement "Dogs enjoy watching TV" does not apply to all dogs. Nicholas Dodman, a veterinary behaviorist at Tufts University said that many dogs have become desensitized, or bored of the idea of television. In many American homes, it's typical to leave the TV on for your animals when leaving so the house feels less “empty”, Dodman reported that while some dogs seem to enjoy the background noise, in some cases, the dog might actually connect the tv being on with being left alone, creating a negative correlation in their head. In short, whether a dog enjoys watching tv or not depends entirely on the dog's personality. It is proven that dogs can engage in watching television, but it's hard to say that all dogs enjoy it.
https://www.petscare.com/news/faq/what-percentage-of-dogs-watch-tv
https://www.nationalgeographic.com/animals/article/150111-animals-dogs-television-pets-science-tv-behavior