Tecumseh arrived, as noted, with a large armed party.

This was deliberate.

He was demonstrating strength, not submitting to American authority.

The visual presentation of his arrival — hundreds of warriors, well-armed, moving in disciplined order — was part of the argument he was making.

His rejection of the chairs Harrison offered was also deliberate.

To sit in the chairs would be to accept the American framework of the meeting, to engage as a subordinate seeking favor.

By sitting on the ground, Tecumseh placed himself in a different relationship to the encounter — equal or superior, not petitioner.