It does for email marketing.

Although images are an important part of creating engaging emails, you need to be conscious of image file size otherwise you may be faced with long email load times.
Our tip: make the images as small as possible without impacting their visual integrity.

The main point of an email is to communicate a message, however long paragraphs of text can lead to your audience tuning out.
Our tip: when in doubt, a good rule of thumb is 40% images and 60% text.

If you’re intending to include a PDF document with your email, think carefully about how you do this. By attaching the document to the email and sending it to large numbers, your email has an increased risk of getting blocked by spam filters.

Our tip: Upload any attachments to your website and link the file location with a snappy call-to-action.

In summary, bigger may not always be better especially when it comes to low attention spans and email marketing.