I haven't concretised my ideas about this ad yet so might come back at some point with some more intelligent analysis, but for the moment:
1) I find this ad especially offensive because it is exploiting the imagery of revolt against oppression (ie associating itself with a positive social movement) while flagrantly erasing all and any aspects of that struggle that could potentially alienate their consumers. All the people in the ad are young and gorgeous, and they seem practically orgasmic with joy; they're not angry, they're not downtrodden, they're not confrontational; they're not threatening the status quo or the dominant elements of social hierarchy in any way. They don't even represent any identifiable group of disadvantaged people. And why are they even marching if they're so damn happy? They haven't even got a cause that Pepsi customers could potentially disagree with. It's brazenly, crassly bland and insipid.
2) The strength of civil rights activism is
collectivity. In the ad the narrative is that one special, beautiful
princess is gracious enough to descend from her ivory tower and bestow the magic of her specialness to resolve whatever non-existent issue the so-called protesters are ecstatically protesting. It totally demeans the idea of solidarity.
3) Kendall is just about the most privileged person imaginable. The whole message of this ad is that privilege is so enchanting that it can beguile the masses into contented conformity. The outcome of her intervention is not that the protesters manage to change society, but that they submit to consumerism and gleefully abandon their protest, reverting to docile obedience to capitalism. Not very progressive.
4) The advertisement is outrageously bathetic. The jarring collision of registers between the renowned image of Ieshia Evans at the Baton Rouge BLM protest and a gigantic corporation shamelessly capitalising on a genuinely meaningful collective expression of suffering and rejection of their excluded status in order to accrue even more collosal profits from selling toxic sugar-water is just shockingly distasteful - even more so when you realise that the BLM image recalls this one from the Tiananmen Square massacre:
Pepsi wants to identify itself with righteous resistance of persecution, but without actually taking any action to justify the association. Pepsi doesn't work to liberate people of colour or combat state brutality in China - the idea of this last one makes me laugh - it just wants to slipstream these movements' credibility to gild its image and garner ever more bloated revenues.
@Ellie The distinction I'd make between the hippy ad you cited and this one is that the hippy movement was essentially optimistic - by crawling on that bandwagon a corporation would align itself with idealism and inclusivity. In this case, Pepsi is trying to link itself to a cause that has at its core a long history of racial agony, but neither offering a solution or even acknowleging that history at all.