If she's referring to a place "online", shouldn't it be "in online" or "on online", not just "online"?
Native speaker’s answer
Rebecca
Since "online" is a place, it does not need "in" or "on" in front of it. Although "online" is correct, this sentence is awkward. This sentence would be more clear if she said "I feel like recently there's been a very noticeable change towards people being a lot more eco-friendly, which has been expressed online."