This is the 2nd "Sticky Mosaic" I have purchased.  Both were huge hits with the girls who received them.
We received a horse one for my 5 year old daughter.  She is crazy about horses and immediately started it.  She completed the 1st of the 4 included posters in conjunction with my help.  The remaining ones she did with off and on help from various relatives, almost like one would do if you were doing a jigsaw puzzle on a rainy day.  The adults and kids involved all had a nice time cooperating to finish the mosaics.  Five year olds will need some guidance to get started, but are capable of doing it independently if the can recognize #'s 1-15.  We thought it was a terrific reinforcement for the #'s she had learned in school.
The Jewelry Box was our second Sticky Mosaic. We got it for our 8 year old niece's birthday.  It was the only gift she wanted to "play" with right away!  It took about 2 1/2 hours for her to do, but when done, it was beautiful!  She loves it and hides all sorts of trinkets in it!