Low quality in my appearance on all zoom meetings since buying this laptop.

I bought my laptop last year 29 January 2023 from a good department store in London London UK.  Due to my profession, I have regular zoom meetings with clients and because of the way I appear on screen with this laptop I have been using my smartphone for meetings ever since, as my appearance is normal while using my smartphone.  On screen with this laptop I look quite distant and do not appear with a clear outline as other participants do, so I went back to John Lewis who told me the problem is with zoom but I do not know how to contact them directly to enquire as to what could be the problem.  Can anyone help me? Thanks, Rachel