Recipients see a large Dropbox folder icon when I'm sharing files to their email from my iPad.

Chat transcript:
( 19:01:51 ) Visitor: I sent a email with a link to a PDF file on dropbox and for some reason, it added a PNG image of the dropbox folder icon. Any idea why?
( 19:02:14 ) Joey: Hello David! Thank you for contacting Dropbox support today! My name is Joey and I would be more than happy to assist you right away!
( 19:02:33 ) Visitor: it wasn't there when I sent the email, only visible to the recipient, which makes it worse because I wasn't able to catch it before it was sent.
( 19:02:34 ) Joey: So, if I understand correctly you sent an email with a link to a PDF file on Dropbox.
( 19:02:50 ) Visitor: Yep
( 19:03:04 ) Visitor: I did a copy and paste from dropbox to email
( 19:03:17 ) Joey: It added a PNG image of the Dropbox folder to the email that you sended.
( 19:03:19 ) Joey: Right?
( 19:03:32 ) Visitor: Yes
( 19:03:47 ) Joey: If you want to share files or folders it would be better to do it by creating a shared link.
( 19:04:13 ) Visitor: why? Why have the other option if it's not going to work correctly.
( 19:04:16 ) Joey: Shared folder is another option, very useful if you want to share a lot of files or even collaborate.
( 19:04:23 ) Joey: Which option?
( 19:04:47 ) Visitor: I clicked on copy link in the dropbox app. Should I not use that?
( 19:04:59 ) Joey: You clicked Share?
( 19:05:11 ) Visitor: yes, and then copy link which is one of the options
( 19:05:26 ) Joey: Yes, this is the correct way.
( 19:05:35 ) Visitor: what would be the wrong way?
( 19:06:03 ) Joey: Copy the URL from the Dropbox website is an example.
( 19:06:17 ) Joey: Drag and drop the photo from your Dropbox to somewhere else is another.
( 19:06:29 ) Joey: Creating a shared link or a shared folder is the correct way.
( 19:06:50 ) Joey: There are some sites that support another option, to upload directly from Dropbox.
( 19:08:25 ) Visitor: Well, it sounds like I did it right, so consider this a complaint. It didn't work the way it was supposed to
( 19:08:57 ) Joey: You informed me that you send an email with a link, right?
( 19:09:33 ) Joey: Was that a shared link for the whole folder or just the file?
( 19:09:56 ) Joey: Maybe you click else something by mistake.
( 19:10:24 ) Joey: *Clicked something else by mistake.
( 19:12:36 ) Visitor: I tapped on share, and then copy link, and then I pasted it into the email. It turned into a blue rectangle that said the name of a file, pdf, dropbox.com. When I look at the same email in my sent folder, or in another inbox folder which I sent it to as a test, what I see is the blue rectangle, but somewhat distorted, and a big icon shaped like a folder with the dropbox icon in the middle, when I open that image, it says it's a PNG file.
( 19:13:21 ) Joey: Can you provide me with a screenshot of the issue?
( 19:16:22 ) Joey: Checking if we are still connected.
( 19:17:31 ) Visitor: Can't seem to paste an image from Photos into this
( 19:17:38 ) Joey: I will now send you an upload button which you can use to upload the screenshot.
( 19:18:13 ) Visitor: File: [removed]
( 19:18:23 ) Visitor: Can you send me another upload button I'll show you the before picture
( 19:19:16 ) Joey: Of course!
( 19:19:32 ) Visitor: File: [removed]
( 19:19:52 ) Joey: So, what is the issue David?
( 19:20:20 ) Visitor: The issue is that great big folder icon, the recipient of this email is going to receive it and they are going to be confused.
( 19:21:29 ) Joey: I will make sure to pass your suggestion to my Team, thank you very much for sharing.
( 19:22:15 ) Joey: Is there anything else I can do for you today in this chat?