After thinking it over, you look back at Dave and nod your head, "Okay. I'll do as you ask..." You tell the painting and pick up the brush from the easel. Dave tries to spread out his arms and legs a bit inside the picture and tenses up a bit before motioning the words "I'm ready" silently to you. You then take another deep breath and get to work with the brush.
You touch the brush to the picture of Dave's hand and with one short stroke, some of Dave's fingers are erased, leaving no trace of them behind, leaving just a slight smear on the end of where his painted form and the brush met.
Dave gasps and his eyes then go wide as he see's his picture in 3rd person suddenly have the fingers on it's left hand get erased and a wave of strange but still highly sexual energy radiates out from where his fingers were erased and ripples through the rest of his 2D body. You quickly touch your hand to the painting and ask Dave if he's okay. Dave take's a moment before replying, "Y-yeah! I'm okay! That felt completely bizarre... It... it's like my fingers were never really there..."
"Dave, what are you saying, I just erased a part of your hand!" You reply worried, but the painting shakes its head and waves with it's other non-erased hand.
"No, no, I mean I feel naturally shaped this way. I know you just erased my hand but this feeling in me is telling me that I was always designed this way, with some of my fingers missing on my right hand. It's really strange... Because... I kind of enjoyed it when you made that edit to me..." Dave replies.
"I guess it works just like how it did with me. Every single brush stroke you put onto me felt completely natural like it was a normal part of me too when you repainted me into a french maid, so that works with erasing things from somebody too?" You say.
"I think so. Go ahead and repaint my fingers... If my theory is correct, they should come back." the painting of Dave says.
"Got it!" You nod and put the brush to the end of Dave's hand. You then start to try to remember what Dave's fingers look like and start to paint. The picture freezes in place to let you work more easily. You remember when Dave made any edits to you you froze up too, so it looks like that works the same for Dave too. Now that he is frozen in place as a still image, you take your time to repaint his fingers and manage to match their detail perfectly, although your not certain if that is the work of the paint brush that the magic canvas came with or your own skill as a painter.
"There, I restored your hand!" You say as you finish repainting Dave's hand. The picture of Dave then re-animates and Dave pulls his hand in front of him, wiggling his fingers. "Look! You got your fingers back!" You shout excitedly. "Yeah, you did a great job repainting them... Strange too..." Dave says.
"What's strange?" You ask.
"Well, it's like the finger's you repainted are just paint... I mean I can feel them and move them and everything just like they are with my other hand, nothing there feels any different or changed, it just... something about my hand feels different from my other one... It's like there there and everything but that part of me is just a painting... Is that how it felt when I repainted you into a french maid Erin?" The picture of Dave asks. You nod.
"I see... I guess that's how it is when you've been edited by this canvas's magic... Anyway... here's what I want to you try next... I want you to...