Since the advent of CGI, practical effects - as in, those made in camera - have become decidedly less frequent than you'd expect.
There are some directors who insist on doing as much special effects in person and on camera as they can, primarily because you can always tell when it's real and when it's fake. Yet, surprisingly, one moment from 'Mary Poppins Returns' looks so good that you'd be forgiven for thinking it's CGI.
The bathtub scene from 'Mary Poppins Returns' sees everyone's favourite nanny simply disappear into a tub of suds, all with a big smile on her face like it's completely normal. As it turns out, there was actually a slide right underneath the bathtub which Emily Blunt fell right down into and slid out.
In other words, an entire set was built for that one moment in the movie. Here's a clip from the behind-the-scenes footage of 'Mary Poppins Returns', detailing how the thing worked.
However you felt about the movie, you've got to admit that it's pretty impressive.
— Alan | CafeFantasia 💫 (@CafeFantasia) January 12, 2019