Desaturate graffiti source and transform to fit on wall. Blend on soft light mode at 50% opacity to give the wall a dirty grungy look. Paint out building in background. Darken footpath using a copy of the section on multiply mode.

Cut out sunflower from background. Cut center away from the petals. Place center of flower over iris on overlay mode. Cut top half of petals from bottom half and using puppet warp, transform the petal layers to fit over eyelids.
Paint some green color under petals and colorize the skin slightly green. Add a shadow behind the petals to make them stand out a bit more.

Apply fractalius filter to eye.

Transform eye to fit wall using perspective warp.

Apply poster edges filter to eye layer and blend layer on overlay mode.
Add sky from sunset source. Adjust colors to match colors on wall.
Add another sunset layer on top of every thing. Blur it 30 pixels and blend on 50% soft light mode. That gives the ground a warmer color as well.
Place another layer of wall on top of everything. Adjust the contrast so the black lines are very black and the light areas are very light, blend on darken mode and adjust opacity.
Add a linear gradient layer to darken the far side of the wall and blend on overlay mode.