There are quite significant differences in the way you can see emails on your phone and on your laptop. Although well said, gmail on phone and your computer would display the same messages but then, they still bear some critical differences.
One instance of what we are portraying here is the means emails render on a large screen device which is not same with the way it does on a smaller one. And now Google is pushing out changes to bring about responsive design for emails in Gmail.
What do we really mean by responsive email design? This means the layout will be more optimized for or suited to your device. This way links and buttons will get sufficiently big to hit on your phone. Equally content will now be spaced in a better way. This extends past just ensuring improved emails on phones. When it comes on desktops, you will even notice some improvements as to the format of emails for mobile for they will now look better on a bigger display.
Most notably, this particularly pertains to emails with appropriate CSS media queries in their design. Google presents a number of help documents for email designers to get better acquainted with the system. This change will be coming in before this month totally fades out, one sure way it could be coming out is an update to the Gmail app.