The extension page at:
https://chrome.google.com/webstore/detail/speed-dial-fvd-new-tab-pa/llaficoajjainaijghjlofdfmbjpebpa
has a mail-to link to contact the publisher. You might try there to get
more focused help on that particular web browser extension.
The Chrome Store page above also has a Support view to show help
requests. You can contact the publisher that way, too. I see other
users reporting loss of images, and the response was to inquire did the
users sync to Speed Dial - which makes it look like the config data gets
uploaded to the publisher's server. Did you enable some sync function
in the add-on? As a backup, apparently you can export the config data
for the add-on, and then later import it, but users report the images
don't show up. When the publisher responds to those help requests,
mostly they say to e-mail them.
Their web site at
https://fvdspeeddial.com/ doesn't list any contact
information, or peer forum to ask other users, or even their e-mail
address (which you can get from the addon's Chrome Store page).