Designs taller than the screen size are not scaled down to fit by default

Summary

When viewing a design attached to an issue, it is impossible to view the design in its entirety if it is taller than the user's screen.

This only affects designs in portrait orientation. Otherwise, images seem be scaled down correctly.

Steps to reproduce

Attach a design in portrait orientation to an issue that is taller than the used screen size.

Example Project

gitlab-issue-examples--shad1w/large-designs-scaling#3

What is the current bug behavior?

The image overflows vertically. It is therefore impossible to view the full image.

What is the expected correct behavior?

The image should be scaled down to fit the screen.

Relevant logs and/or screenshots

See example project

Output of checks

This bug happens on GitLab.com

Possible fixes

(If you can, link to the line of code that might be responsible for the problem)