Hi, Henrikh.
Thank you for pointing this out! It looks like a new “feature” from Coursera. I’d never noticed it before until you pointed it out just now. It does seem to work as you say: it creates a “zip” file called Files.zip containing the entire directory tree for the assignment. In the few experiments I’ve done so far, it seems to download the entire tree, regardless of your current working directory with the UI. I double checked that it correctly handles linux “symlinks”: there are several assignments with large pretrained models or large input files which are structured as symlinks pointing to a file in a different “read only” subtree and the zip file contains the target file, not the link.
But I did find at least one Course 4 assignment where the “Lab Files” button does not show up: the Face Recognition assignment in Week 4. In Week 1 of Course 5, only one out of the three assignments has that button. So it’s not universally available apparently. I’ll keep an eye on this.
Note that the reason you can’t directly download .mat or .h5 files is that browsers typically won’t let you download arbitrary binary files in formats that they don’t recognize. But they will accept standard “archive” formats like zip and tar.
Up to this point, we have recommended that people use “tar” to package up the files in a given assignment for download, because the Docker images for the assignments do not contain zip. Here’s a thread about how to use tar, but you’ve probably already seen that.