Immigration officers and what they see when you scan passport [USA]

I know immigration officers can see your history of travel, arrest warrants if any and your entry/exit out of the country. I went on a holiday last week and changed my flight to arrive back into the USA a day later (born/live in the US) and the immigration officer said my flight was previously the day before and asked why I changed it. I enjoyed the country the a lot so decided to fly back in on Sunday instead of Saturday. Curious why this would be asked?