The key feature of the Epson 1650 photo scanner that made it a photo scanner was that the lid for the scanner had the ability to be a light source. From the product brochure:
This allowed one to scan their slides and negatives without getting the higher end specific purpose slide scanners (example: Nikon Coolscan 5000) which tended to be much higher price... and you couldn't use a slide scanner for prints or other general scanning.
The flathead photo scanner was also able to scan medium and large format film. The 1650 advertised an "Optimal 4"x5" transparency unit" which was likely a different (switchable) lid with a larger light area.
If you are scanning slides or negatives, the Officejet will not do it at all. On the other hand, if you are scanning prints, either will do it and the Officejet may do it better.
The line of photo scanner made by Epson is apparently still in production. For example, the Epson Perfection V600 Photo Scanner - note the media being scanned and the light source in the lid.