A preview of your liking which will excite viewers to click on your work. Perhaps a collage of snippets from each artwork, or one artwork which you like best and the text "click for more" or whatever, be creative :)
but what to use as small image?
By collaging all the images on one canvas and uploading that as a single submission.
how do I showcase them all together in one submission?
These are nice works, but if you don't think they are even worth giving a name then we don't think they are worth being showcased in the gallery. Since they all seem similar, why not showcase them all together in one submission? Thanks!