Seabrig29,
To expand on TGiles' comment, what is updated is the "7.5 Service Desk installation binaries (setup files)". What that meanss is, that your actual running Service Desk install is not touched. Even if it was running on-box with the SMP it would not touch the SD install itself.
To upgrade the SD install it would be necessary to use the SD install binaries to run throguh the setup/configuration, just like you may remember doing when you first installed SD :)
In the end it's a matter of words and word choices.
Regards,
Rasmus