The advertisement is running on TV and is as far as the average human a completely normal ad. However dogs can hear sounds at much higher frequencies than us, Bakers have make use of this by adding a high frequency sound similar to that of a dog whistle which attracts the dogs to the TV in the hopes that the owners will associate this with the dog liking the product.
Tests of this high frequency sound during the research phase showed that 100% of the dogs reacted to the noise, and some dogs even approached the TV.
More information: http://www.dailymail.co.uk/news/article-2100108/Pitched-directly-dogs-advert-whistles-Frequency-far-high-pet-owners-hear-it.html
