Station 3 - Station 3 has Telavi and Khartals both instruments are small , telavi is small with a string that is attached to two balls and khartals is a wooden rectangular with medal in the middle to make a sound. There is no shape similarity. The sounds are different , telavi when you shake it from the strings it sounds like a salt shaker and khartals sounds like more like the instrument RIQ.
Station 4 - Station 4 had mbira and santoor and they are both medium size but, Santoor can become very large. There is no shape similarity because mbira square like a book just like santoor but santoor can become large and have rectangular shape. The sounds are very different , the santoor to me sounds like a violin being plucked by its strings and mbira sounds like someone is beating a light wooden instruments .
Station 5 - Station 5 had Djembe and Damroo both are very different in size djembe is very big and damroo is very small ,but shape similarity is almost exact the only is that the damroo has two ropes with a little bead that makes the sound for the damroo and for the Djembe you have to tap your hands on top of it to make its sounds. The sounds are the same they make thump sound just djembe is loud and damroo is very light because of its small frame.