Zillow just updated its Zestimates of house values. If you follow Zillow's estimate of your house's value, you might want to check it out now and see if it changed.
Zillow made two changes. First, they improved how the Zestimate is calculated and, second, they changed how they report the accuracy/inaccuracy of their Zestimates.
Every year or two, Zillow will make a major improvement in how they calculate their Zestimates. According to Zillow, their newest system can now "see" the photographs of houses in listings and can "distinguish between high and low-end finishes" and can "incorporate the value of features like updated bathroom fixtures, fireplaces, and remodeled kitchens" into their Zestimates.