Design Generator - what to look for?

Question

css

Hello.
I'm writing this design generator (just started).
The purpose of this creation is to give the real designer an idea of ​​the client's preferences. And the client should be given the opportunity to quickly visualize something for the designer without knowledge of HTML / CSS and then comment on what needs to be added, etc.
What are the main points (in terms of design) to pay attention to and what elements are necessary for editing by ordinary people who are not familiar with HTML / CSS, etc.?
(I'm not a designer myself)
Thanks in advance for all the advice and suggestions!
UPD: example

Answer 1

Essentially, you are writing a prototyping tool.