How do I change my default photo on Airdrop?

Hello support,

I've been trying to fix this problem for awhile. When my phone pops up on Airdrop, I see a photo I want to change. No matter how many times I change my iCloud default photo, the photo stays the same.

This continues with email as well and other services. How do I change the image that pops up when my iPhone appears on Airdrop?

Any help is greatly appreciated.