Issue with images dimensions when using the API

[Pedro Cunha]

TL;DR: I have a JIRA issue that I want to duplicate using the API. The issue's description includes images. Unfortunately, I must be misusing the API. Although the images are correctly attached to the ticket, their dimensions are incorrect. The "description" markdown between the original and duplicate are the same.

These are the steps I am doing using the "rest/v2" APIs:

1. Fetch the original JIRA issue - including attachment information
2. Create a duplicate issue by copying the following fields from the original JIRA issue: summary, description, labels, attachment
3. Download and upload each attachment from the original issue to the duplicated issue synchronously

I have attached a screenshot from the original and duplicate item dimension weirdness. The markdown does not render correctly either (look at the list numbers in the second image). The issue auto-resolves after manually editing the duplicated issue, which does not work for me.

Any tips to debug the issue? Incorrect escaping somewhere? 

Thanks