Here’s how to compare the DEGAS and Zlaty Jeweler files (or certificates) in Nancy Drew: Mystery of the Seven Keys.
You must obtain the file from Vladena’s safe, and then talk to her about it. You will also have had to talk to Elka about computer protection and then find the laptop charger at the cafe, adding it to your inventory.
Look at your laptop, then use the laptop charger on it. Open the email and click the download file button. Close out of the email and click on the file on the desktop.
Solve the captcha image puzzle. You will need to scroll left and right on the email to look at all the pages in order for Nancy to comment on it. You can then spot the differences from the Zlaty physical paper (on your right), and the email on the left by DEGAS.
Green dotted lines are matching data, while the red are discrepancies. Your task will be done when Nancy closes out the computer and paper scene, and comments on the discrepancy.
Check out the video for the full guide and explanations: