in the documentary ‘the life of tove jansson’, theres mention of thingumy and bob and how they represent tove herself and her female lover at the time, vivica. thingumy and bob speak a language that only they can understand and carry a suitcase that they always try to keep hidden containing a ruby 

the ruby represented their love that they had to keep hidden away from society and the groke, who chased them for it, represented a sort of fear. i think they also mention how the story of moominmamma immediately being able to recognize moomin (despite not looking like himself), or rather the whole book in general, reflected that tove’s family had accepted her love of women

edit:

u can watch the documentary on youtube here!

It also puts into perspective a couple of her other stories like Comet in Moominland which was written during the war, and you can see how that influenced her work too (the comet itself representing the atomic bombs for example)