Not necessarily. Sometimes they just sit down to relax. I used to ride a horse that was so lazy that when I'd go to fetch him from the field, he'd remain sitting down until I got right up to him and attached the lead rope. He'd realised that the end result was the same whether he came to me or I came to him!  Edit: however, you're right in that I doubt any horse around that monstrosity is at all relaxed.