Cultural appropriation is a discussion for experts not lay people. While that might sound snobbish remember it is an academic term used by people with a deep understanding of economics and culture. Today it is tossed around like an old coin and as such has become diluted, mocked, woke and trivialized.
It has always served racismto misunderstand any concept in order to better dismiss it. We live in special times. The flourishing of ignorance. When the mainstream gets hold of terms and just runs with it blindly. And then the blind come and counter that ignorance with more ignorance. Has anyone readFourmile, Henrietta (1996)? Nope. Racists get terms that expose them and twist them around to destroy their utility. So even today we will find out how even the racist can populate social media with the myth of White genocide. Every term used in liberation has been flipped: woke, social justice, Afrocentric. And what they have not flipped they have demonized; Sharia, etc. So that the mere mention of them causes you to run for the hills in Africa.
Dressing up as "another culture", is racist, and an act of privilege. Not only does it lead to offensive, inaccurate, and stereotypical portrayals of other people's culture ... but is also an act of appropriation in which someone who does not experience that oppression is able to "play", temporarily, an "exotic" other, without experience any of the daily discriminations faced by other cultures.' ~ Kjerstin, Johnson
While cultures have always been exchanged between different groups what cultural appropriation deals with is when those exchanges involve trivializing and forms of economic exploitation. It is something powerful groups do to groups with less power. It is not cultural appropriation when concepts of beauty are forced onto oppressed people and then they adopt (through racist indoctrination and cultural genocide) them, losing their own culture in the process.
Cultures adopt aspects of each other all the time. This is fine when both cultures are exchanging equally — called “Cultural Exchange” — but if there is a power imbalance between the cultures then it is not an equal exchange. If a minority culture is adopting aspects of a dominant or colonizing culture in order to fit in or survive oppression then it’s called “Cultural Assimilation”. If it is a dominant or majority culture taking aspects of the minority culture and taking them out of context of that culture and profiting by them in some way the original culture is not free to do, then it’s called “Cultural Appropriation” (or “Cultural Misappropriation”) —Lauren Panepinto
You cannot just look at Picasso and label it as cultural appropriation. This is why it is a discussion for people who understand the topic and the issues.  
If you study Cultural appropriation and how it has been used especially in Critical race studies you will find that cultural appropriation specifically has been a way of explaining cultural exploitation by the dominant race class.
This can be especially controversial when members of adominant culture appropriate fromminority cultures — Wikipedia
Someone on Quora saidno such thing as cultural appropriation there is just culture. This is why Quora is dangerous. This person has no qualifications to discuss even culture. Cultural appropriation is not about one culture necessarily owning an item, like jazz, braids, or Afros. It deals with where someone who has privileged power or race can go and take something associated with a particular culture,mock it, and exploit it trivializing it in the process. All of those conditions must be met. And it is highly subjective and something experts discuss, not clowns on social media.
Picasso borrowed or was inspired by African art. Is this the same thing? (2) Not really. All art borrows.
Is the above photo Cultural Appropriation? No because we sold him the clothes for an African event. Ocacia makes African clothes for everyone. Same way Europeans make suits for everyone. We at Ocacia own the profits and the skills. 
Today what lay people are replying to when the topic comes up is the lay usage of the term! not the social studies or cultural studies definition of the term. And idiots discussing topics beyond their pay grade is one of the dangers of social media. They dont have a clue, never studied CRT, but are experts on why it is so wrong. So a wrong concept leads to
Is wearing braids as a White person racist and cultural appropriation?
Why do Black people appropriate the hairstyle of white people and dye their hair blonde and make it straight?
the Dashiki was taken from Ethiopia and commercialized in the 60s. Today it is made in China and sold back to Africa. Some have argued that this was a form of cultural appropriation/exploitation.
If a White woman braids her hair I dont think that is something to fuss about because braids are not an explicit cultural thing globally. A White woman going to an Ethiopian wedding and wearing Ethiopian clothes is NOT cultural appropriation either.   But would it be respectful to put on a Hijab for fun and a mini skirt and go out clubbing and drinking? No. Studying and playing Jazz as a White or Japanese person is not in this context.