KTXH has been using this name for quite a while which makes them as another MNTV O&O station not calling themselves simply "My (channel number)." It's similar to other Fox-owned duopolies that make their MNTV counterparts drop their name to "Fox Plus" (i.e Dallas, Phoenix, San Francisco, Minneapolis, and DC). But unlike other markets, Houston's MNTV station is closer to the VHF band than KRIV so it wouldn't make sense to call themselves "Fox 26 Plus" if the MNTV station is lower down the dial (which is my guess why they chose the "My 20 Vision" name instead).