JFC do you even understand why CDNs exist in the first place?

This is an app level optimization that nobody outside the primal app benefits from.

If you're so scared the event itself, not where any given image is hosted because ffs CDNs are an industry standard precisely for scalability of different types of clients and subject to the same potential tampering, was modified then the burden of proof is on you to whip out them raw logs and packet captures with actual proof of EVENT manipulation not a screenshot of a CDN optimized url.