Yes, you can choose the devices on which you wish to display your optin forms on (Desktop, Tablets or Mobile).
To modify your display settings, follow the few easy steps mentioned below:
Step 1: Click on the form that you wish to edit in order to disable it for the mobile users.
Step 2: Navigate to the Behavior step, scroll down, and expand the Display Rules in the left menu panel.
Step 3: Select the devices of your choice. Click on the Mobile device option in order to disable it.
Step 4: To publish your form, navigate to the Publish step, and toggle the Publish this form button to blue. Click on the FINISH button to activate your form.
That's it! Your form has been successfully disabled for mobile users.