Depending on your client you use and depending on relay settings for mirroring other relays you can post on one single but still show at some others.

This is amethyst for choosing where to post.
https://image.nostr.build/737a1240cbbdbdfd293503e2882723f5d06f16daef2defa42c77bcf929e7d3f6.jpg https://image.nostr.build/af5ad9bb13a8a8a13f7b02d3666bf86009bff56c8db68e539bc6eadbb75370d0.jpg