I'm guessing the mathematical diagram doesn't count for Focused because it's a drawing, not a painting. Other ways to get the emotions you need are to watch the Romance channel for flirty, and get a MySim trophy, watch the Comedy channel or take a bubble bath for Playful.
I agree Confident is the easiest one to get though from the mirror or even just from painting. My Sim will often get confident from painting and I'll take advantage to quickly paint three Confident ones afterward.
Another tip you might not know is you can make three paintings of the same emotion and it'll count. It doesn't need to be three unique emotions. So, take advantage when your Sim is in a certain mood and you'll be finished in no time. :)