Hi Tela,
From the screenshot, it seems you are using EasySocial's comment form. Since that's the case, you have to disable image attachments in the comment in EasySocial's comments setting. Once you do this, commenting in EasySocial also does not allow users to attach images.
Settings>General>Comments>Attachments>Allow Image Attachments In Comments(
http://take.ms/BZRhe)