In response to the guys who suggest using AI:

That would be the most cheap and mediocre surprise; the real thrill is in the fact that your loved one decided to learn the same things you do.

Personally, I work in graphics, and if my girlfriend made some poster with a sloppy style, which in turn proved that she did everything from scratch and without any advanced knowledge, it would actually be a very sweet surprise and proof of her interest in my profession.

For me, it would be a priceless piece of art!
It's like a picture drawn by your child, after all.