Linux Mint has a silly thing, where there is a banner across the top of the file browser when there are certain file types in the current directory. For example, the one that annoyed me most read "Media contains digital photos". Why does it feel the need to tell me? Here's how I got rid of it, thanks to this source.

Add these lines to ~/.local/share/applications/mimeapps.list:

[Removed Associations]
x-content/image-dcf=gthumb-import.desktop;
x-content/image-picturecd=gthumb-import.desktop;brasero.desktop;

Then update the mime database and restart caja (closes all your open file browsers)