Others have this mostly covered it seems, but I'd add: it's easy to get discouraged when you start a painting, because everything looks rough, flat, and badly-proportioned. A lot of people tend to give up there, but the trick is to keep putting down more paint. Paintings by talented artists look the same as a bad sketch when they first start and only have one layer of paint down, but by the time a good-looking painting is done there are many layers of paint on it.

In addition to the deconstructions other people have made, anyone who knows Latin well enough to leave a hidden message would know that 'cu' and 'im' aren't Latin words. 'I want' in latin would (most likely) be either 'volo' or 'cupido' and the one which fits better with the message, 'cupido,' means 'I desire' more in the sense of lust, or physical need. 'I' in Latin is 'ego,' and is an auxiliary word one would not include in a secret message. 'Im'? I don't know where they got 'I.' And furthermore, 'si' only means 'unless' with a stretch of its real definition 'if.'