Google has implemented an Android mobile platform update that has removed the check boxes next to emails in the mobile
Gmail program. The check boxes have been replaced with the contact's
picture. If there is no contact picture, it instead shows a colored box
with the first letter of the contact's name.
An example can be seen below:
Article ID: 386, Created: June 11, 2013 at 2:48 PM, Modified: October 14, 2013 at 2:14 PM