I just got the same thing, but it looks like the text came from my own number. Went through the same process you just did with the same results. Was curious too since I've never received this message before and am able to get picture texts.
I understand wanting to find out who sent you the picture message. Have you checked your usage details on My Verizon to see if you can find the specifics? The website you mentioned is our picture messaging portal, which you can reach at www.vzw.com/picturemessaging Sometimes, the link in the text message may not direct you to this website I mentioned above, which will display any of your picture/video texts. Please let us know if this helps.
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