It could be that your desktop relays have not picked it up. Copy the noteid from the mobile client and paste it into the Iris search box on the desktop and see whether it comes up.

If you're sure that it is published you could try to "Resend to relays" from the note menu.

Iris uploads them to www.nostr.build so that's a possibility that something is not working on their end. Yet, if you can get the picture URL from the original post (for example, "Copy raw data" from the note menu) and you paste it on a browser you can verify whether it's available.

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