I did a quick search and found lots of list and description posts, but not ones that match your use case.
Can you post a few links to some standard examples?
I’m thinking you would use the share sheet from Reddit to trigger the shortcut. The shortcut grabs the page, extracts the images and then parses the HTML for the first comment and the author data. These then get saved to files, in the formats described, in your Obsidian vault.
The vault location is potentially a point of contention. Shortcuts can currently only save within certain locations and if your vault is elsewhere then you would need something like Toolbox Pro to enable folder bookmarking as a workaround. But IOS15, due for release relatively soon, will natively address this limitation.