The most recent version of the Google App, which is version 6.7.13, appears to have code found in the APK that points to the addition of a Lite Mode that is to be designed for use in regions where data is not as readily accessible. Google has been very open about connecting people in emerging countries, and they have initiated a number of projects that aim to help them further reach their goal of connecting the next billion people to the web. While many places globally do have some form of internet, it may be much more few and far between than in areas like the U.S., Europe, or larger countries in Asia, or those regions may simply not be able to use as much data due to costs, and this is where a Lite Mode option may come in handy.
While this doesn't seem to be accessible from the Google App as of right now, it's also very likely that it won't be meant for use in the U.S. or larger more developed nations that already have a strong network set up for internet. For those areas where this will end up becoming available, Google looks to be giving users control of a few things, like whether or not the Lite Mode feature automatically enables itself when needed. If users would rather have more control than that, there looks to be an option to either disable it completely or keep it turned on at all times, and if the image below is any indication, it cuts down on web use partly by making images smaller and more to the size of a thumbnail instead of using larger pictures.
When this is a feature that will be made available in the regular version of the Google app is still unclear, and follows a change to the beta version last month where Google removed any of the references to Google Now. In addition to adding a new functionality to the beta, Google is also testing new features in the regular Google app as well, as they have recently changed the name of the new Dashboard tab in the app that was being tested to 'Upcoming' and they have rolled the test out to more users. If you want the latest version of the Google App beta, you can pick it up from the button below.