Pretty sure that this is badly wrong.
The part number in the photo is a SO-DIMM. The part number in the link is a DIMM. Unless Purism is doing some seriously weird stuff, a DIMM simply can’t be inserted and if you really tried to force it, you would just break something.
For DDR4, SO-DIMM has 260 pins while DIMM has 288 pins. SO-DIMM is typically used in laptops and other devices where space is at a premium. DIMM is typically used in full sized desktops.
The width, notch and pitch are probably all different between DDR4 SO-DIMM and DDR4 DIMM.
Here’s what I believe to be a correct link: Kingston Technology ValueRAM 16GB 2400Mhz DDR4 Non-ECC CL17 SODIMM 2Rx8 (KVR24S17D8/16) Green : Amazon.com.au: Computers