Printing photos on a HP Color LaserJet 2550

This command prints nicely coloured photos on the laser printer:

lp -o scaling=100 -o landscape
 -o PageRegion=A4 -o PageSize=A4
 -o HPOption_PaperPolicy=Scale -o HPEdgeControl=Off
 -o HPColorSmart=Automatic -o HPRGBEmulation=Vivid
 -o MediaType=Glossy photo.jpg

The media type will probably have to be adjusted to match the paper used.
This command will show all the available options:

lpoptions -l