It's not a lie.
Booking has received tremendous regulatory/legal scrutiny on that group of features and they wouldn't be caught red handed doing something indefensible in that space. That being said, there are clearly some decisions to be made about what "currently looking at" means: As engineers, we all know that nothing is tracking user eyeballs (thankfully), so in reality these things are necessarily implemented as a rolling sum of non-bot page views within X minutes.
Whether or not the information is correct, of course, doesn't mean anybody has to like the feature. I personally really don't like it, but acknowledge that it was a feature with shockingly significant business impact when first released.
Source: Used to work there. Read the respective code at the time (~2015/2016 or so).
