The email signature looks just fine on your machine's Outlook!
Why does it look different on your boss's new laptop?
Why does Outlook make your emails look distorted or increased in size for some users?
The culprit here is DPI scaling, a windows setting to aid readers with visual difficulties. This issue is cropping up more and more as new high DPI laptops often have the setting enabled by default.
What is DPI?
DPI, or dots per inch, is a measure of how many dots (or pixels) can fit within a given space.
This issue affects Outlook (desktop)
If you know HTML, you can start HTML coding your email signatures to accommodate users with desktop scaling.
The challenge for email signature designers is that Outlook doesn't read the HEAD section of the HTML when the email signature is pulled into Outlook > Learn more.
Here's a link to Microsoft support article.
Workaround - How to set Display text size to 100% (default)
Reset your display size to 100%.
On Windows 10 you search 'dpi' and change to 100%:
When using older Windows 7, navigating to your display settings > Make text and other items larger or smaller:
Here you select 100% (default):