As far as I can tell the default it display only. When I upload via a different FTP client, I am able to specify which one is chosen, but it defaults to the "Display only" settings.
The API documentation for EM claims that there is a setting that can specify whether the job is print_ready, but PM doesn't provide the value to EM, letting EM use the default. Here is what the documentation says:
METHOD: POST
Input:
<uploadjob>
<gallery uri=".../rest/gallery/sports" /> # required
<settings
email_account_yn="0|1" # optional, defaults to user config
process_subgalleries_yn="0|1" # optional, defaults to user config
print_ready="0|1" # optional, defaults to user config
rotate="0|1" # optional, defaults to user config
position="0|1" # optional. 0=put images at the start of the gallery, 1=at end
/>
</uploadjob>
PM send an empty settings key which should be OK since all of the settings are optional. They're supposed to default to your user config settings. You could contact them and ask them to see if they're handling the optional settings correctly.
In a future version of PM, we could provide that setting and set it to a default (print_ready="0")
-Kirk
