Very strange... your exact code is working for me when I send an email to myself from Airtable's "Send Email" automations.

See both of my screenshots below.

Perhaps your browser is blocking the loading of certain images?

If your browser isn't blocking anything, then you may want to report the issue to support@airtable.com.

Alternatively, you can try sending your emails with Make's advanced automations & integrations, and see if it works there.

If you’ve never used Make before, I’ve assembled a bunch of Make training resources in this thread. For example, here is how you would instantly trigger a Make automation from Airtable.

Hope this helps! If you’d like to hire an expert Airtable consultant to help you with anything Airtable-related, please feel free to contact me through my website: Airtable consultant — ScottWorld

In your screenshot the Airtable logo isn't loading up either, so it seems likely it's localized to your environment somehow.  Does the email look like that on another device?  What about on another network?

As I mentioned above, the browser is most likely blocking images.

Thanks Scott - strangely, when I changed the email source to outlook from the native airtable automation, it worked fine. But I agree must a local issue as the original worked when I sent to a gmail test account!

Thanks, I think you're right, seems a local issue. It worked when I was using my home wifi, also worked when sending to a test gmail account.