The design of the characters is very interesting, Mashima is obviously using references from his previous works. But that is common for the Japanese Mangakas, many of them use very similar designs because in the end, they are their creations and they work with a peculiar style.
The original design for the protagonists, the design of Jellal and the existence of Plue are marks of Mashima, so to see them should not be strange.
I hope to see what it generated, after all he said he wanted to create new characters.
With the image of Natsu and Lucy eating ice cream I love it, hopefully follow Mashima creating more that fit very well.