Large datasets don't show variables with down arrow in Environment

I think I've found a small bug in RStudio Cloud. I don't have this problem on my desktop, so perhaps it's a RAM issue? If you have a large-ish dataset loaded in (e.g. diamonds) and try to click that little blue down arrow next to the dataset name in the Environment tab, it does not show the variables. With a smaller dataset (e.g. mtcars) the button works fine.

I did some experimentation to try to discover where the limit lies,

It appears to make the distinction at 512 Kb. So, my guess is it's not a "bug" but a "feature" as they likely have coded it in such a way that showing it in the environment requires making another copy of the data.