Pixave 1.0.5 provides 3 options for thumbnail.
To select thumbnail type, Please follow the below steps:

1. Open Preferences
2. Select “Previews” Tab
3. Select thumbnail type in Thumbnail Option

If you’ve selected thumbnail type, this option will be used when image imported.

Default thumbnail type

Aspect Ratio thumbnail type

Size to Fit thumbnail type

If you want to update the existing thumbnail with the new selected thumbnail type, Please follow the below steps:

1. Right mouse-click in Browser

2. Hold “Option” key and then Select “Rebuild Previews…”