Although it doesn't look to be very wide spread just yet, it seems like Google is doing some testing on the visual appearance of the history for their Search widget, more specifically for the dropdown box that shows up when you start typing. If you typically use the Google Search box widget on your device, you'll likely notice that the history will pop up with past searches just as it does on the web interface or within the Google mobile page, and this is the element that Google looks to be testing a visual change to, as some users have reported seeing the history show up with results as side by side blocks as opposed to a longer list.
The benefits of this as well as Google's reasoning for the visual changes should be rather obvious, and are likely to help save space on the home screen and keep things more minimal and organized. It's stated that this is the default visual appearance for some, but for those that are seeing things as normal which is just a list of a few search results line after line, it's actually possible to make this new look show up with a quick few taps.
All you have to do to get the search results to show up in the history with the new design is tap on the search bar from the widget or from within the Google app, and before you start typing anything to begin the search, tap the space bar first, then tap a few letters, and then delete everything including the space. This should force the new look to visualize for you which doubles up search history results onto one line to save some room on the screen. It's possible that this may not show up using this little trick with every single set of letters that you type, so if it doesn't show up the first time simply close out of the Google Search bar and try again while typing a different few letters after the space to see if it shows up. There is no mention from Google about the visual changes, so there's no telling when or if Google has plans to roll this out to all users as a standard.