...at TSX tragically humorous:
Time Bid Ask Last
15:20 28@$5.18 27@$5.22 $5.20
15:22 5@$5.19 6@$5.22 $5.20

For a while most bids and asks have been one to a few lots. As soon as the 27 lots came up on the ask so did the 28 on the bid. Note that over this two minute interval no shares were traded. So when the 27 lots on the ask went to 6 i.e. 21 withdrawn, 23 were also withdrawn from the bid side.
I interpret this as a buyer waiting for sufficient lots to appear on the ask side to make it worthwhile, someone who has to pay higher commissions and the one lot offers are not worthwhile to him because of the commission cost. Similarly on the ask side, but neither wanting to come to the other's price for the three cents.
This is what one lot bids and asks do, they stiffle possible trades from high commission clients. And that is how the one lot offers maintain control over the share price as long as they remain close to what the market offers.
For the same reason they are usually the first to scoop up any sizable offers.
Do not be one of those that has been fooled into believing that the price of the one or two lots presented as the price. They are often head fakes to get you to sell at their price.