Calendar icons show weight increasing?

I might be reading this completely wrong, but the icons shown on my calendar show my weight as increasing.

I've been manually inputting my weight over the month (it's going down!) but the icon that appears is a set of scales with an up arrow indicating weight going up! Shouldn't the arrow point down to indicate a loss?

Even the filename for the icon being shown is: calendar-bg-weight-increase.png

I'd expect that to be calendar-bg-weight-decrease.png!