Nobody notices a pfp change if it happens one pixel at a time. Upload your current pfp and the new one, pick the exact pixel it starts growing from, crop the new photo to a circle, then drag the slider — 0% is a single pixel replaced, 100% is the new photo filling the whole frame. Three effects get you there: grow expands a circle outward from that pixel, zoom dollies the camera into it until it fills the frame dead-center, and original size grows the new photo's own patch in place with no camera zoom. Save any frame in between and set it as your pfp for a few days before anyone clocks it, or grab a zip of 10 frames spread across the whole sweep for a slow-reveal sequence.