I don’t think this is actually a Picasso, and I believe the signature isn’t his either. I looked for this image among Picasso’s known works with guitarists but couldn’t find it anywhere online. It seems more like a piece inspired by his style.
Discussion
You might be right. The image does look a bit off at the head, I have to be honest. We know Picasso had many works in which he explored the styles. So maybe this could be a study?