The phrase
"to scrape the sides of the bowl" means to use a spatula or similar tool to gather and mix all the ingredients that have stuck to the edges of a bowl, so that nothing is left behind.
Full definition
Once that's all incorporated add the sour cream and vanilla and mix on medium speed until combined,
scraping the sides of the bowl down if necessary (it probably will be if you don't have one of these).
The coolest innovation here (apart from Breville's predictably swish aesthetics) is that scraper beater with flexible edges that
continually scrapes the sides of the bowl like a spatula - reducing mixing times by up to 60 per cent.
Gradually beat in the sugar and continue beating,
scraping the sides of the bowl often with a silicone spatula, until the mixture is very light in color and texture, about 5 minutes.
Beat two 8 - ounce packages of Cabot Cream Cheese in a large bowl until creamy, adding in sugar, Cabot Plain Greek Yogurt, tapioca and eggs, and vanilla, beating and
scraping sides of bowl in between the addition of each ingredient, as detailed in instructions below.
When the chocolate begins to set,
scrape the sides of the bowl and mix in.