Hi Mark,
When you Copy, it's the source program in combination with the OS that determines what variants are placed on the Clipboard [a service of the OS].
When you go to Paste, the program being used assesses what's being presented on the Clipboard & in which ways it can interpret that information.
The 'change' you're experiencing could be due to a difference in either or all of the 3 participants -- Source data format, Target program interpretation (in this case, it's Office), OS Clipboard management.
As an example of this behavior, I tried copying a JPEG via the Preview app and used Paste Special in PowerPoint. The only option I got was to Paste the image as TIFF.
But when I first paste the image normally into Word, and then re-copy the image from Word to PowerPoint, the option to Paste Special as a JPEG showed up.
As a workaround, you may first copy the image into an Office document and then re-copy and paste it into PowerPoint using Paste Special.
I know that this is not a perfect workaround; if you are unsatisfied, we’d suggest posting to the
Office 2016 for Mac forum as this is a client related issue and they are experts in this field.
Also for your reference:
In the paste special, I no longer have the paste picture option.
Regards,
Sheen