Have you ever purchased art on board a ship?  I see many passengers doing so but I never found any that I liked or had room for in my condo.  On our Transatlantic to Southampton from Miami on Princess, my first cruise on Princess, my husband saw a 3D signed piece on the Beatles crossing Abby Road that he wanted.  I did purchase it.  It is not actually "art" but I purchased it for him at an art auction for a "good" price.  It has a special meaning for us because my daughter lives close to Abbey Road & we watch a Cam from there every morning on our computers.  Then we know what the weather is like there.  We also photographed ourselves crossing Abby Rd.  Lucky for us, drivers expect tourists to do this & don't run them over.  In fact, there is a entrepreneur photographer on site who will take your photo if you left your camera or phone home.   What fun.  Do this on your next visit to London.