Attachments are not included in the email. You can use the variable {ticket.has_attachments} or {ticket.reply_has_attachments} (See https://docs.blesta.com/display/user/Support+Manager) to notify the recipient if there are any attachments on the ticket.
If you think attachments should be included, I would suggest opening a feature request thread. I can see the benefit, but there are some things to consider when emailing attachments such as the size, whether they could be construed as malicious by spam filters, how many attachments there are, etc.