As far as I can see you can only add full pages not items on a specific pages. So you can add a new page but not edit an existing.
Can you insert an image into a PDF in Preview?
No. You need the professional version of Adobe to performplex operations. If the document is based PDF you can open it in a Word Processor like Word. Add the image to the document and then save it as a PDF.
How can I create a shortcut to insert a time stamp into any application, on macOS Sierra?
EVERY file already have time stamps for Create Date Last Modified Date and Last Opened Date. Is this not enough? Historically revision control and build tools have used these existing timestamps to do everything they need. Most likely these are sufficient - lots of smart people have thought about this kind of problem for a long time. You could also create a file tag that includes an arbitrary date.
How do I insert an image in an answer or question details on Quora?
Free-form question details no longer exist. For more information see Sumi Kim's post in Product Updates board_item board_item_id 351261
How do I know if a product’s “made in (insert country)” stamp is actually the country the product was made in?
You don really know with any certainty. In some countries it may be only the stamp or label that was made in the country thereon. In many other cases it could be that only a certain percentage of the product was made in the claimed country of origin. In most manufacturing processes you can end up with a product that has multiple source countries involved and possibly only final assembly or value adding performed in the claimed country of origin. I should add that this is the norm for the greater percentage of products on the market. Apart from very nasty low end products there is nothing wrong with this. We enjoy quite cheap items at point of purchase so it no big deal to throw it away and get another when it fails. Yes it wasteful but who wants to pay double or triple the purchase price for a repair even if a repair is possible.