This dapper looking man is Al Jolson, a Jewish singer, entertainer and actor who was incredibly well known in the early 20th century. He is noted for developing Jazz music and popularizing it. In fact there have been many who have said that Johnson was to Jazz what Elvis Presley was to Rock n' Roll. One of his more notable achievements was his role in the first full-length feature to have sound, the appropriately titled The Jazz Singer.
Here is the finale from that film, in which Al Jolson sings "Mammy":
Yes that's Al Jolson, and yes he is wearing blackface makeup. Blackface, or the practice of white performers putting on makeup to look black was extraordinarily popular in Vaudeville acts and films from the early 20th century. The makeup featured a darkened face and overly big lips to convey the stereotypical black person. Obviously this practice is viewed as utterly disrespectful in today's world.
As a side note, before you judge Al Jolson too harshly, he is pretty much singlehandely responsible for bringing African-inspired music to the masses. He was also heavily involved in fighting for black performers' rights on Broadway. His use of blackface was usually employed as a metaphor linking the suffering of the Jewish people with that of the African-American people. It still doesn't make blackface right, but I don't think Al Jolson was any kind of monster.
So what does this have to do with Pokémon and Jynx? Well, let's take another look at Al Jolson wearing blackface makeup:
Now let's see the original design for Jynx:
Notice any similarities? Nintendo ended up getting a lot of flack for this, as many people felt Jynx resembled blackface depictions. The heat grew so intense that it was not long before Jynx's official design was changed, swapping her black face with a purple one.
Contrary to what many people thought, the design of Jynx resembling blackface was most likely a very unfortunate coincidence. With her golden hair, big lips and red kimono, Jynx resembles a monster from Japanese folklore called Yama-uba. This monster was said to live in the mountains, and it would lure unsuspecting people with dancing, before devouring them. Yama-Juba is often portrayed in Kabuki theater with black skin. Since multiple Pokédex entries note Jynx's predilection toward dancing, it's easy to see how they could be related.
Yamanba, a Japanese Noh play which has been performed for centuries, feature the Yama-uba and it is from this play that the popular physical attributes of the creature are derived. The play also inspired a very popular fashion trend in Japan during the 90s. Yamanba and Manba girls in Japan have extremely dark tans (or sometimes just flat-out black skin) crazy eyeliner and facial stickers. It's possible the creators of Jynx were mimicking this fad as well. So the original design of Jynx is most likely not based on racist stereotypes. No, it is most likely based on the bizarre fashion sense of Japanese women. Or it's possible that the creators of Jynx somehow had access to a time machine, and decided to base Jynx on the crazy hip-hop artists of the 21st century. Who knows.