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Ginny has indicated (through a notification request) that she is waiting on Washer 2. Now, when she returns to the home screen, she can view a count-down at the top that tells her how many minutes there are left until her robes are done washing.
Analysis
Learnability
Overall, this design has few learnability issues. The home screen shows a clear list of open washers and dryers, and it is intuitive and externally consistent that the launderer should click on the down arrow to learn more about the options for a particular washer. One issue, however, is that it is not quite clear what "Idle" means here. The idea is to provide two descriptions - "free" and "idle." "Free" means that the machine is empty and ready to be used. "Idle" means that the machine has finished its work, but the previous user has not removed his/her clothing yet. We might consider somehow making this distinction more clear.
The expanded box of options is also pretty self-explanatory. The fact that you can view notes from a previous user and leave your own notes is clear. The "Notify Me!" button may, perhaps, be ambiguous in this view. It is meant to give the user a way to "listen" on this machine and receive a notification the next time it has finished running (this assumes that the user plans on running this machine for him/herself). However, some users may think that they will be notified when the machine has turned from idle to free. Perhaps we can give a more descriptive button in this place.
In addition, though the system of messaging between users is very simple to use, it is not explicitly stated that the messaging will be anonymous. This is something that a user may want to know, so we should probably indicate it somewhere.
Efficiency
This design seems very efficient. It does not force the user to wade through any of the more time-consuming features (leaving notes, messaging other users). But if a user is interested in using these features, they are at least implemented in a minimalist way.
A high proportion of our users are probably only interested in using this app to remotely see if any machines are open. In this case, the user only has to open the app to the home screen to find out all they need.
It is slightly less efficient to force users to click on a down arrow to view more details about a machine, but doing away with this would make the home screen much less clear and very busy-looking.
One efficiency problem is that, when a user wants to leave notes about laundry care, the chances are he will be leaving the same note every time he uses the app. This design does not allow storing and re-using previous notes, but it's definitely something we should include.
Safety
There are a few safety issues we can see in this design. Firstly, there is no up arrow in the expanded options box. This should be included, as the box takes up a lot of space on the screen and it would be nice for the user to re-collapse it upon clicking it (accidentally or not).
When the launderer views a message left by a previous user and interacts with this other user, we should be sure to include some way for the launderer to review this interaction, in case he forgets the specific instructions. Perhaps this messaging system should consist less of individual notification messages, and more of a continuous dialogue screen, showing the whole history of messages. The user should not be expected to recall the entire conversation.
In the current design, it isn't clear that the user can edit the note that he has left. If a user has left a note for a machine, we should change the options box from "Leave a note" to "Edit your note."