Based on selection of file type conditional validation is applied
{{userInfoFormGroup.controls.fileType.errors.extension.message}}
This field only allow file extension as jpg or bmp only.
{{userInfoFormGroup.controls.profilePicture.errors.extension.message}}
If you want to apply conditional validation on 'Image File' then you need to add 'File Type' input as 'Picture'.
{{userInfoFormGroup.controls.imageFile.errors.extension.message}}
This field only allow file extension as .vcf files.
It shows custom message
{{userInfoFormGroup.controls.contactFile.errors.extension.message}}