Jesus was teaching me and others what should be understood in giving alms, offertory, genuine help. The lady here gave what she had for the time but not for the show to the rest watching her doing what everybody should be doing. Jesus knew very well from his Godly knowledge that all those dropping money into the treasure had different amounts of money and different motives of offering how much they offered.

Jesus would like all of us to give out what we have in a positive motive, positive attitude rather than pride generated offerings.