mate-screenshot:tldr:42f52
This command, mate-screenshot --effect=${select}, launches the mate-screenshot tool with the --effect option set to ${select}. mate-screenshot is a command-line utility for taking screenshots in the MATE desktop environment.
The --effect option allows you to specify a specific effect to apply to the screenshot. In this case, the value ${select} is used as the effect. However, since the value is enclosed in ${}, it suggests that it is a placeholder or variable that should be replaced with an actual value.
Without knowing the context or where this command is being used, it is not possible to determine what the ${select} variable represents, or what effect it will apply to the screenshot. The actual effect will depend on the specific implementation or customization of mate-screenshot in your system.