Is there any way that I can....

[SweetCarolineConfect]

permanently keep my shop in thumbnail mode instead of as a list when someone clicks on my shop? I feel like you can have the prettiest pictures but they are not fully appreciated if your visitors go into your shop and see these teeny tiny thumbnail pics (and not everyone knows how to switch to thumbnail view).

Does anyone know if there is a way to keep thumbnail view fixed so that it is shown that way when someone stops by your shop?

[MythOfTheWild]

If someone wants to view your shop as a list then you're not able to stop them. You can keep it in thumbnail view for yourself whereever you are, of course, but each person has their preferences.
I prefer to view by thumbnails, but other people prefer to view by title. This is beneficial to people whose photography isn't their strong point.

If you really want people to see your thumbnails, ensure you have the "featured listings" setting turned on, and just select 5 or 6 of your best pieces. Only 4 will be visible, but when one sells, it'll be replaced by another. That's the only way to ensure thumbnails for people viewing in lists.

[SweetCarolineConfect]

Thank you Kim! Appreciate the advice!