E-mail tracking creates visible space at top of e-mail

I’m sending transactional e-mails using Brevo and I can see that at the top of those e-mails, there’s a 1x1 image from sendibt3. However for some reason the containing div is about 20px tall. Is there a way to fix this?

I can also see from another thread that it’s not yet possible to disable tracking in transactional e-mails. It’s also handy for me to be able to see the tracking. So I’d prefer to find a way to make this actually invisible.