Link to the original paper: https://arxiv.org/pdf/1508.06576.pdf
The problem is to take two images, extract content from one image, style(texture) from the other and seamlessly merge them together into one final image that looks realistic.
left:content img, middle:style img, right: output img
[1] A Neural Algorithm of Artistic Style by Gatys et. al - https://arxiv.org/abs/1508.06576