Happily! This was posted for sale on ebay at some point, it may even still be there, but it was interesting enough to save the images posted. In fact I'll post both this and a brochure for the "standard" Bernoulli box which used the 11-inch cartridges. No interior on that one, sadly, but we do get the stats on the back. As you can see, the original 10MB cartridges (and the later 20MB ones) are 0.71 x 8.23 x 11.02 inches, whereas the 5MB Macintosh cartridges (which got their own unique drive due to Macs not having SCSI at that time) had 0.53 x 5.5 x 7.4 inch cartridges, so not-insignificantly smaller. But other than some grainy magazine ads, I have yet to see any actual photos of the cartridges. I've attached an example which is probably the best I've found so far.
Of course, once the Plus came out, Macs came with SCSI standard, and they discontinued the B105 Mac version of the Bernoulli drive and just adapted the original 10 and 20 MB drives for the Mac (they originally used a weird 37-pin D-Sub and a custom SCSI adapter card for PCs.)
EDIT: My guess (and it's just a guess) as to why they gave Macs a smaller cartridge size of only 5MB is probably to do with the pretty significant limitations of the original Macintosh File System, which from what I have read starts to really choke with large numbers of files. By the time Macs got SCSI, HFS had been released, and so it was much less of a problem than it had been previously. (Early serial-based HDDs like the GCC HyperDrive encouraged users to partition their drives into multiple volumes, even with the drives themselves only being 10-20MB apiece, in order to get around MFS's limitations in that regard.)
