Increase picture thumbnail size in Mint 20.x file manager

I want to increase the picture thumbnail size in Mint 20. When I did a google search it came back with: it's because they are bigger in file size than what is configured as maximum "thumbnailable" size. But that can be changed: In Ubuntu 20.04, In a Nautilus (file manager) window > Hamburger menu button > Preferences > "Search & Preview" tab > Thumbnails section > "Only for files smaller than" and then you can give however large value you want. Does this mean I must install Nautilus in order to increase my thumbnail size? Please advise.

Chris