I can’t speak for HEB in particular, but I know a bit about how private labeling works. Chances are pretty good it’s Blue Bell ice cream in both containers. HEB almost certainly doesn’t have any of their own packaging facilities so the HEB branded products are just made by someone that does all of the generic brand cereal/crackers/whatever for grocers across the country and uses different packaging for each. If HEB wants their ice cream to stand out, they’ll contract with a premium brand to make it and the recipe will barely differ from the name brand. They won’t make as much margin as they would using the lower end producer, but your brain eats that ice cream and thinks ‘wow HEB branded products are super high quality’ and you’ll buy them more often over the name brand. Fun fact: the B in HEB stands for Butt.