this article situates instagram as a continuation of the genre of european oil painting. the point of both is to asert social status. oil paintings were about showing your material possessions and cultural refinement. instagram is about what you've got, how awesome you are, how delicious your lunch was, how well thought of, respected, popular, hot etcetera you are.
john berger talking about european oil painting sounds like he's talking about instagram:
he makes the distinction between what the genre as a whole was about and what specific works within it were about - suggesting that the works that we now remember from the period went beyond showing off. there might be some other, more interesting thing to do with instagram (or with social media in general) than looking good or looking better-than-you. i wonder what that might be?