A regular ongoing project has multiple tasks/modules being executed on day-to-day basis. Client’s life becomes really easy when they get regular updates about what’s going on. Predictability (more on that soon) of updates ensure there is no anxious moment for them.
But at the same time, there should also be a room for demos too. All the updates are fine till client get curious what’s actually is being built.
Let your clients know when they could expect demos of the ongoing work. Weekly, bi-weekly or maybe have a QA site where latest codes are pushed at end of the day. Let your client see what’s being worked upon.
I usually roadmap a project with demos in mind. For example, what is the smallest feature set that my project teams can show in two weeks, then in 4 weeks and so on. The initial demos can be just the bare-bone of the requirement, something really raw.
For agile projects, demo anyways is scheduled at the end of each sprint and here having a QA site works best.