Dominik There's a little manual work-around with which you can give images any size you want. Instead of the default syntax, use this BBcode-style syntax and you can specify width and height:
[img width=100]https://bunq-prod-together-files.s3.eu-central-1.amazonaws.com/2021-02-04/1612464733-734082-screenshot-20210204-194207.jpeg[/img]
Looks like:
You can also specify "height" or both.