In this companion illustration we see Jim hiding from the slave hunters, and to me the image does create sympathy for the vulnerability of the fugitive. MT's text is more factually descriptive: "He was in the river, under the stern oar, with just his nose out." A few lines later, however, Jim thanks Huck for "sav[ing] ole Jim--ole Jim ain't gwyne to forgit you for dat, honey."
The Barrett Collection, UVA PS1305 .A1 1885b