But, to her surprise, the height of the trolley fits perfectly above it.
“I just learnt the small trolley fits at Woolies self serve,” she captioned the video.
Her discovery was apparently news to many, who replied to the clip in earnest.
“I worked at Woolies for three years and had no idea,” one said.
“Life-saving information, thank you for your service,” another joked.
The five-second video has since been liked more than 17,000 times and shared online almost 1,200 times.
7NEWS.com.au is seeking clarification from Woolworths whether the fit is by design or just lucky coincidence.
It appears from other commenters, however, that only the smaller trolleys fit.
This story first appeared on 7NEWS.com.au