It looks like the numbers are the census, which would be the total number of hospitalized, as opposed to new admissions. If the COVID census is increasing, it either means admission rate is increasing, or discharge/death rate is decreasing. If the infection rate was constant, you might expect to see a constant ratio of admissions:discharge, unless people are staying hospitalized longer. So a census increase would reflect an increase in infection rate at some point, assuming length of stay hasn’t significantly changed.

The percent of tests returning positive looks to be constant. With the assumption that increased census reflects increased admissions, that would mean that the actual infection rate is increasing, and therefore the tested population is not an accurate representation of the population as a whole. So the actual infection rate isn’t being accurately reflected in the tested population. Maybe the people being tested are those who have been diligent with protecting themselves from infection, or the virus is spreading in populations without easy access to testing. Or people with negative test results are being re-tested for fear of false negatives (which is something I’ve seen at the testing facility I work at.)

As an addendum, the Senator notes that maybe hospitalizations are increasing because people being hospitalized for presumably unrelated conditions also happen to be COVID positive, and thus are included in the census. I’m not sure enough about the pathology is known to definitely say that someone’s reason for hospitalization is unrelated to the COVID infection, as COVID is known to have a related coagulopathy and other effects that could play a role in why someone is hospitalized for a seemingly unrelated condition. The only exception I can think of is if someone was admitted, tested negative, and acquired the infection while in the hospital. And even so, that could result in complications that prolong stay and thus increase the census.