To piggy back off of @palash-toshniwal:

I was not able to get the attachment to not show in the inbox but to avoid the "download" and "add to drive" options in gmail when hovering the image while reading the email, I simply wrapped the <img /> tag with a <a href="yourURL"> tag.

<a href="yourURL">
    <img src="cid:logo2" />
</a>`