Those multimedia messages the creator sends for you to purchase, but you havent's purchased yet will not be shown.
This Chrome extension is very easy to use, just install it on your chrome as an extension from the above-mentioned link.
The process is similar in Firefox.
Vimeo leaves the choice of whether or not the download button is available to content creators, which is pretty cool.
You can then try posting it again at a better time, with a different caption, or even decide to send it as a direct message.
Use this simple manual on how to download OnlyFans videos to understand what each method entails.