I wanted agent Perry's outfit to reflect the noir detective film aesthetic canon Perry kinda has going on. Overtime I made it a priority to show agent Perry's design to be more closed off and secretive. His hat is very important to his agent design and how I would imagine him animated as a character. To understand what I'm specifically taking about with Perry tilting his hat and hiding behind it I want you to go to Micheal Jackson's Smooth Criminal music video and pay attention to the way he keeps tilting his hat forward, because that's EXACTLY what Perry is doing. Also pay attention to how his character is choreographed to have his face is shadows most of the time, human Perry would be mysterious at first with a shadowy face. It visually tells the viewer that his agent persona shadows over his authentic personality. Ideally I think Perry would initially keep himself as hidden as possible when he's a new nemesis to Doofenshmirtz. Gradually Doofenshmirtz sees his face more clearly and it makes Heinz happy when he can get Perry to smile because he thinks it looks precious

Agent Perry would slink around like the Smooth Criminal music video, maybe not as exaggerated and dancy but something along that vibe. It's because he's a cartoon but also agent Perry is genuinely trying to act cool and low key. Very serious and dramatic. At least until Doofenshmirtz questions who he's trying to impress acting like that. Then he feels a little embarrassed and self aware so he becomes more casual and stops putting on an act. Perry has a facade of being serious and tough. But overtime Doofenshmirtz brings him out of his shell and discovers that Perry is actually an adorable dorky softie.

I wanted it to be visually clear that Perry is happier retired over being an agent. His face and hair isn't hidden, it's in full view. When he's an agent his hat makes his eyebrows harder to see giving him a more muted facal expression and to show that agent Perry masks his emotions. He's experimenting with a different hairstyle that he's never tried before. In this picture I actually tried to recreate that big teethy grin Perry does in canon sometimes, specifically when he's looking at Santa in that one episode. It looks less awkward on him as a human I think lol. He's more self expressive and relaxed.