It is unknown why the two were there. Both are under WWE contract, with Velasquez' deal running until fall 2022 and Rousey's deal running until April 10, 2021. Velasquez hasn't been seen on WWE television since losing to Brock Lesnar at WWE Crown Jewel 2019. Meanwhile, Rousey hasn't been on WWE TV since losing to Becky Lynch in the main event of WrestleMania 35.
Velasquez was at the WWE Performance Center in February, resuming his training after getting his knee scoped.
PWInsider notes that the first photo is from the company cafeteria while the second photo is from a hallway on the executive floor at WWE HQ.
It is unknown when Velasquez will return to WWE television. It is also known when or if Rousey will return to WWE television.