It seems you're referring to the liquidation of a long position on $SEI likely Sei Network with a value of $25.4K at a price of $0.399. A liquidation of a long position occurs when the price of the asset falls below a certain threshold, causing the trader to lose the margin they used to enter the position.
In this case the market price likely dropped below $0.399 resulting in the liquidation of the long position. This means the trader had to sell their $SEI holdings at a loss to cover the margin.