The main difference is in the visual appearance of the labelling/advertising of the two. The supermarket labels tend to use a lot more type and are more informative than the billboards. As seen in the Steinlager billboard, the focus is on the imagery and use of colour, rather than information. It suggests an idea, rather than informing a decision.
What’s the same?
I found it interesting that both these images/objects immediately drew my eye. I think that both images have used the colour of the objects themselves and the simplicity of that to sell the product. For the fruit, they are kind of selling themselves, and so the packaging does not need to be as suggestive, but the Smirnoff ad uses the enticing qualities; colour and texture of the fruit to sell their image.
It also shows the common goal of both sites of selling an image, but also highlights the differences between the sites in that their method of this advertising is quite different, as is their target audience.