Theme Implementation
Players experience the theme through a dual-gameplay loop, each one implementing the theme and the special object respectively.

The gears appear in the micro-managing part of a factory machinery, being vital to maintain the "Boss Happiness" meter. You have to "do your job" so the boss, ergo the enemy, does not appear as often. You do it as an in-lore tedious (but fun in gameplay) obligation, but it's ultimately a cover for your real goal, sneaking away to paint.

Special Object addition
Following the theme implementation, the brush is the tool which you use to paint, the actual fulfilling objective for our character (and the only lucrative one). It serves as the player's in-lore source of income, as "selling" paintings gives you money. Reaching 0 money makes you bankrupt and you lose, but leaving it exposed when the boss arrives triggers an instant Game Over due to being laid off, so you have to balance both aspects.