Grande herself has often spoken out about loving animals and being vegan - which has left many social media commentators confused.
The singer posted pictures of herself wearing a Starbucks apron holding the new Cloud Macchiato, which features espresso, foam, and caramel drizzle. She tagged the image #starbucksambassador #trythesoyversion - though Starbucks has confirmed that the drink cannot be made vegan.
"Ariana Grande is the so-called 'fully vegan' that's why we're disappointed, because she could have gotten another vegan option into Starbucks," one Twitter user explained. "If it were me I would've said this would be drink will be vegan or I will not be supporting this, because that's what vegans do."
"Why would you collab on a drink that isn't vegan since you're all about the animals?" one person asked.
"Even a soy version has eggs in it though," another added. "The cloud powder is egg whites. Just not sure why you would be an ambassador for this particular drink if you're vegan. Would have been nice to see you use your influence for a plant-based food option or a drink that can be made vegan."
Grande has previously come under fire for collaborating with MAC cosmetics - which tests its products on animals.