There are some fundamentally different ground-rules and even limitations, when designing for digital - and especially so when you are aiming exclusively at mobile.
I want to highlight a couple of blog posts and our PDF specifications for starters - you might have already read them, though:
In summation, a really great catalog experience on mobile requires:
Making the most important information or action accessible and readable without having to zoom.
Having fewer products on each page, and instead larger images.
Larger texts. Everything (almost) should be readable without having to zoom.
Avoiding Serif fonts. They do not perform optimally on displays.
Using CTA's that clearly indicate their purpose - and stand out from the background on which they have been placed. (use icons - not drawn links)
Being able to find additional product information at a click (in-catalog or on website).
Great examples of catalog design intended for mobile:
https://viewer.ipaper.io/prodigioso-volcan-1/revista-desigual-prueba-5/
Single or few products on each page.
Visible CTA's with clear visual presentation of purpose/action.
Large, legible text (without zoom).
Enrichments; animation, video and galleries help to create an engaging catalog experience.
Static navigation (top right) help the visitor quickly navigate.
https://viewer.xdcollection.com/xd-design/dk/xddesignbobby20
Single or few products on each page.
Visible CTA's with clear visual presentation of purpose/action.
Large, legible text (without zoom).
Enrichments; animation, video and galleries help to create an engaging catalog experience.
Static navigation with visual indication of current section.
http://avis.skousen.no/tilbudsavis/NOuge5Basic_korrektur/
Single or few products on each page.
Visible CTA's with clear visual presentation of purpose/action.
Large, legible text (without zoom).
Additional product information available via popup.
Enrichments; animation, video and galleries help to create an engaging catalog experience.
https://viewer.ipaper.io/avon-western-europe/uk/2019/04/c04-instant-brochure-colour/
Catalog designed exclusively with mobile in mind.
Single or few products on each page.
Visible CTA's with clear visual presentation of purpose/action.
Large, legible text (without zoom).
How To Shop guide (page 2)
Additional product information (some with instructions for use) available via popup.
The catalog format (print & digital) exists to inspire the reader - so that you as a company can turn the reader into a customer by presenting products the reader did not yet know they need/want.
It should never be reduced to a product grid, (like on webshops) as the magic will be lost!