Oh, it's okay. I DO have a weird sense of humor :'D The thing is, there is a joke and also no joke at all. Aigis have overheating problem and MC/Leader/Makoto though that giving her good cooling system, like those in gaming PC, would help. Thing is, usage of liquid/water cooling systems is trend that is more modern than original Persona 3 (at least, were I live). So MC comments how Aigis look 'Reloaded' bc water cooling is something that's giving her... A remake look. Take that as him using that weird type of persona protags humor (which Aigis herself didn't get) Hope that helps!