The blackish area at center is the partially-shadowed vent of Coronet Geyser, a small hydrothermal feature in the Geyser Hill Group of Yellowstone's Upper Geyser Basin. It's rarely reported erupting, but it was active with small splashing in June 2024.
The ~bluish-water filled vent just behind Coronet Geyser is apparently an unnamed feature (click on the photo once or twice to zoom in and look around).
Tags: Coronet Geyser geysers Hill Group Upper Basin Yellowstone Wyoming June 2024