When a map gets reloaded due to an asset change, its spritesheets get reset to spring:

Repro steps:

1. Create a mod with this code:

    /// <summary>The mod entry point.</summary>
    internal class ModEntry : Mod
    {
        /*********
        ** Public methods
        *********/
        /// <summary>The mod entry point, called after the mod is first loaded.</summary>
        /// <param name="helper">Provides simplified APIs for writing mods.</param>
        public override void Entry(IModHelper helper)
        {
            helper.Events.Input.ButtonPressed += (sender, e) =>
            {
                if (e.Button == SButton.F12)
                    this.Helper.Content.InvalidateCache("Maps/Farm");
            };
        }
    }

2. Load a save in winter and exit onto the farm.
3. Press F12 to reload the farm map.

Fixed in develop for the upcoming SMAPI 3.0.