I think you’re right - it’s like this issue in the border syntax
Luckily for the particular issue with the image component anvil has a dropdown of allowed values for display-mode
for the width self.image_1.width = "default" works for me
Other valid values are basically anything css like
https://www.w3schools.com/cssref/css_units.asp
so "50%", "300px", "auto", "80vw"…
I think anvil will allow any string and if it isn’t valid then it will default to default so
self.image_1.width = "blah" is parsed but ignored