TBQ and Keren both point out quite rightly that Angel(us) draws and paints; Spike wrote poetry when he was human. Having Angel write a poem to Spike or Spike sketching Angel lying naked in bed, doesn't work, and can make you look like, well...like you haven't been watching the show(s).
Though I can see it working in a situation where the author makes it obvious that she's aware of that fact -- for instance, Angel making fun of William's bad poetry, and modern-day Spike challenging him to do better -- or Spike repaying Angel's gift of a naked painting of the two of them together, with stick-figure porn.
Not what I was going to say. What I was going to say was, Joss sort of buggered up his own canon, and confused the newbies, on the drawing!Spike issue. Spike's little shrine to Buffy in the basement of his crypt includes several sketches of her -- so unless they were ones that Angel did, and Spike managed to steal them from Buffy, or rescue them from the mansion/factory-ruins, Spike can at least sketch.
Note that I'm not suggesting people should run with this -- I'm more pointing out that Joss and co. can be just as guilty of muddying their own continuity. Granted, they're allowed, because it's their continuity, or lack thereof -- but it still makes me want to grab somebody and say "Look, we have a group of about 20 diehard fans with eyes, memories, critical thinking skills and in some cases postgraduate degrees. We'll work for free. Please? Please?